Trading a cheap upper for a P11 tomorrow and don't know a whole lot about them. My only experience with KT was a PF9 years ago...

I carried a P-11 for several years in an ankle holster as a BUG when my Agency issued 5904’s.  The Kel-Tec P-11 could use the S&W 59 series of mags but the MecGar 59 series mags had a thicker body and didn’t work.   I did something stupid with my P-11 shortly after buying it.  A Friend wanted to dry fire the pistol so I unloaded it.  Instead of unloading the mags I dropped a spent 9 MM case into the chamber and dropped the slide.  The extractor hook snapped right off.   I should’ve unloaded the mag and fed the spent case from the mag, sad part was I knew better.

I called Kel-Tec and told them of my dumb mistake and they told me to send it in.   My Dealer Friend sent the pistol via USPS to Kel-Tec who fixed my pistol and returned it to me free of charge.  They also cleaned up the trigger pull free of charge.   I carried that pistol about ten years till we transitioned to Glock.  A Friend without much money was looking for a cheap pistol and I sold it to him.  I had the clip mounted on the frame and used to occassionally carry it off duty if I was making a quick trip to the store.   I normally carried a 3913 off duty but it was handy to grab the P-11.

I had no trouble shooting my P-11 and usually aced our secondary weapon qualification.  I could get good body hits out to 25 yards and I liked the sights.  The P-11 has significant recoil and you felt it in the web of your hand and is very similar to the PF 9.  I think I normally carried my P-11 with the flat mag base but if I only had the P-11 I carried the mag with pinky extension or 5904 mag for a spare.

The Kel-Tec is not a gun you take to the range for pleasure shooting and compares favaorably with a J frame S&W, as neither are really fun to shoot but easily concealed.  Back in the late 80’s to early 90’s the P-11 was about the only cheap pistol I’d trust.  My P-11 was totally reliable except for where I broke the extractor.  I carried DA revolvers and DA/SA pistols so I really never had any issue with the KT DAO trigger.  I shot a couple Friends Taurus M-111 G-2 pistols and I would pick the KT P-11.  The Taurus trigger system just doesn’t work reliably for me as I get failure to fire because of the trigger blade safety.  At least my P-11 always went bang for several thousand rounds.

Today i would prefer to carry my Glock 43 or a Glock 26/27 but there are worse pistols than the P-11.  Kel-Tec was one of the first to introduce a really compact 9 MM pistol with 10 + 1 round capacity.

P-11 is my EDC with 1 +12 in the pocket

Like their PF9, the P11 has a very long trigger pull.  Mine is long and kinda heavy, but very smooth and consistent.

It's not a plinker; it's work to go through a box of rounds with a P11.  But to me, is a solid and reliable carry pistol.

Edited for spelling.

I've got guns that are more expensive, some with better sights, some with better triggers... but the P-11 seems to be the one that gets  carried the most.  It's light, compact and the belt clip is extremely convenient and comfortable.

Double strike capability is nice.  The sights are plastic junk.  No idea why Keltec didn't make the PF-9 and P3AT double strike capable as well.  Dumb move.

I got one cheap.  Like it for summer carry.  I stuck a Tanfoglio rear sight on it and it shoots point of aim.  Long smooth trigger as already mentioned.  S&w m59 mags I think.

It'll take any of the S&W "classic pistol design" double stack 9mm magazines.  My wife has a 469, which will take my 559 mags; the 469 magazines work in my P11 just fine.  Come to think about it, I haven't tried the P11's magazines in her 469...they may be identical.

S&W 59 mags fit the Marlin Camp 9 and some KelTec SUB 2000s as well.

It's like a lot of manufacturers said "Why should we design a new magazine when Smith already did?"  You see that a lot with guns "based on" other guns (CZ70 clones, etc.) as well as newly designed guns that fire common calibers (Taurus' Millenium Pro line apparently works fine with Sig 226 magazines).

This is actually good for us and the gun manufacturer.  We get guns that run with readily available magazines (and often these mags are less expensive because they are made - and sold - in higher quantities), and the manufacturer gets a reliable magazine they don't need to sweat much about.

I just checked, and the factory magazines for my wife's 469 work perfectly in my P11.  So do all my "classic" double stack Smith magazines, including the handful of .40 mags that I bought hoping I could use them in my Daewoo...  No luck there, but I have several more magazines that feed 9mm just fine once I eliminated the bumps S&W used to keep goofballs from trying to put .40 magazines (filled with .40 rounds) in 9mm pistols.

The only mags that wouldn’t work in my Kel-Tec P-11 was MecGar.   The bodies were larger diameter than factory S&W mags.   I never tried them but my understanding is the mags from 4006 would work in P11 with 40 S&W conversion barrel slide.   I carried a P-11 in an ankle holster when my duty weapon was a 5904 and used S&W mags in P-11 a lot with no issues.

The OP was six months ago.

If the P11 had a better trigger, it would have been the P365 over 20 years ago when it came out.
It's small, light, and held 10 rounds until lately, now 12 will fit in the grip.

The main thing that has kept it from greatness it the trigger.
The pull weight can range from 9-11 pounds.
I handed mine to my 16 year old son and wondered why he wasn't shooting.
I looked over and his hands were shaking.
He couldn't fire a shot.
If you only have a P11, or you also shoot revolvers, you may not mind it.
I shoot Glocks and other guns,
I would take a Kel Tec to the range one day and make a fist sized group from 10 yards.
The next trip would produce a "pattern".

I've owned several, just never could be consistent because of the horrible long, hard trigger pull.
I started shooting guns with nicer triggers and never looked back.

The Daewoo DP-51 also.

The P11 is my favorite carry and I'm just about ready to buy a PF9 to go with it. The P11 is an amazing pistol that I believe is the safest gun you can carry. There are many reasons; first, the lightweight firing pin with a strong spring makes it extremely unlikely to have a 'drop-fire'. Actually I don't believe you induce an inertia-fire by any method including throwing off of tall buildings or putting in a vise and hitting with a bat - it ain't going to fire. Second, the hammer is concealed and can't be touched except at its rearmost travel and because of the action type it can't be cocked anyway. It always rests on the firing pin when not being cycled. This is safe because of the previous point - no inertia fire possible and being concealed at that point there's no way you can snag it on anything that might 'pop' it and cause a fire. Finally its the action itself with its long, hard trigger pull which basically is the only 'safety' - that pull is not going to happen by accident.
No manual safety is required for all those reasons, so you carry it loaded and its always ready to fire. I absolutely trust mine and I judge any small carry pistol by it - most fail. You can learn to be accurate with it. My grown son proved that to me - I thought it couldn't shoot inside of a pie plate at 10' but he proved me wrong. Since then I have doubled-down on my technique and now can shoot it pretty straight. I did make a small adjustment on the sights.

with a 12 round mag you will have 13 rounds, if all you have is a 10 round mag, it can be modded to 11. the lonnnng trigger can be mastered.

I've got 2 of them.  A blued one and a stainless.  They're good guns, but light and some people have problems shooting them because of that.  There have also been some people who have had issues you can address w/ what they call a fluff and buff.  I personally haven't had any issues w/ mine which weren't aftermarket mag related during the ban.

If you do have problems, last I heard they had good CS and will take care of it.

Don't dry fire them.  They break parts from what I've been told.

'not dry firing' is a rumor. The only thing is you can't pull the trigger with the slide off which you wouldn't do on any pistol. If you do the hammer linkage slips out of whack but after you put it back together and pull the trigger again it resets.

I had one , good gun for what it is . S&W mag thing is good too !
I gave it to my 32 year old daughter , I love my daughter so if I though it was sub par she wouldn't have it .

I carry mine, mostly in the summer. As I'm getting older I have a hard time racking the slide.
Still take it to the range occasionally, but as stated above not the most pleasant gun to shoot. Three, four mag's worth and I'm satisfied.

Got a used one last week.  I bought spare mags too.  Went to shoot it last Saturday.  Holy crap.  I could not believe how bad I shot with it. I admit it ran 100%, but I lost two rounds out of a b27 target at 7 yards.  I have never had that happen. I can hit at 25 yards with an LCP, so this upset me.  I'm in the fence now in trading it in.

The P11 is essentially a semi auto J frame revolver.

If I had to toss a semi auto loose in a coat pocket, or carry one clipped IWB without a holster, the P11 would be it.

Practice with that long, heavy trigger and you’ll get better.  Mine has a very consistent, if long and heavy, pull, and it’s tiring to go through a box of ammunition with it, but once I got used to the trigger - and ensured my overall hold was solid - I can hit a 6” circle at 15 yards every time, mostly in the middle, too.

you have to learn how far to pull the trigger before it goes bang

I cut my teeth in LE with .357 revolvers. This thing is worse. I can't believe it. It's just a little monster. I fired mostly 115 FMJ, but I also ran some 115 JHP and 147 Win Ranger T. Again, it was 100% reliable. I got the gun cheap for $150. I figured why not.  The only thing I did was polish the feedramp and touch up the light scuffmarks with perma blue. I painted the front sight dot orange as well.
All 3 magazines are factory 10 rounders.  All work fine but have the notorious rattle

the mags can be modded and then will hold 11

The trigger pull shouldn’t be quite that hard.  There is a mod that will reduce the pull weight some, found here.  I haven’t tried it yet, but when I get around to it, I plan to check it out.

The P11 uses magazines that are identical to classic S&W auto pistol mags except for capacity.  Since I happen to have two different S&W classics (a 469 and a 559), I’ve positively verified that both the 12 round 469 and 14 round 559 mags work fine.  Yes, they protrude a bit, but I think of them as back up magazines.

Ok. Went out again with it. Put. Quick 54 rounds through it.
25 X147 AE FMJ
15 X 115 blazer brass FMJ
10 X 115 aluminum blazer FMJ
4 X 115 hornady American gunner XTP JHP

All 100% function. I realized about round 20 that I was holding a death grip which led to two rounds again going out at 10 yards. I loosened my grip and let the gun recoil on its own. I literally had my shots group closer.  I had to just figure this gun out. It’s definitely different than all my striker fired semi auto guns

You don't want to mess with the trigger pull too much as that's the safety.
I never did get that FP9. I was going to sell my FEG PA63 because the de-cock lever was so hard to move - I thought it would be too involved to get it ready to shoot (no safety except the de-cock lever - it could be carried in DA mode, hammer down, or even cocked and not locked with the lever in 'Fire' position). Since I am not about to carry in those modes, I decided to get it out and take another look. I found I could thumb the lever with my strong hand in a forward sliding motion with the weak hand getting its grip, all in the motion of drawing and presenting. This puts it in DA mode with a very decent pull (since I modified it). Now I have confidence in my ability to get it out of the holster and into action with no delay. I have been practicing this movement and I feel pretty good about it.
The P11 is still my overall favorite carry because its the only pistol I know of that can be handled and carried loaded with total safety - it is not going to fire without that long, hard trigger pull, and I have not thought of any circumstance where that is going to happen by accident. The hammer cannot stay cocked. You can't manually draw the hammer back or catch it on anything - its inaccessible. With the small Titanium firing pin and strong spring, there is no possibility of drop-fire - or throw-fire - or drop off the Empire State bldg. fire. The thing is an inert object until you pull that trigger - you really have to want to shoot it.

Lol the original sig killer, had one and it worked well enough but let it go to my brother some time ago when he couldn't afford Romain noodles.

If you have a file and some patience you can get the mec gar mags to fit.  Some cold blue will clean up the look and hold off the rust some.  It takes a little doing but I've been successful with it.  

Mine picked up a trigger reset issue but I think that the Mcarbo trigger kit has fixed it.  Needs a few more mags through it to be sure.  

These are so cheap that you can try some amateur gunsmithing with them and not feel bad for messing them up.  They are the same basic size as the new "micro 9mm" pistols but have been around for decades and are half the cost.  Once you get into one you find out that they're pretty simple and easy to maintain.   Also you can find parts pistols on gunbroker from time to time on the cheap.  These will have everything except for the serialized frame usually.

I carry the P11 more than I carry my G43. It's also the most accurate 9mm I have.

The only issue I've has was the slide lock on an empty mag.  So, I happened to be near Cocoa Fl one morning and I stopped at KelTec. I gave the P11 to the young lady at the counter, telling her the issue and began giving her my info to mail it back.  She said "if you have 45 minutes, have a seat in the lounge and we'll be with you shortly".  45 minutes later she brought out my P11, they had gone through it and replaced 5 parts that were worn. She said they put two mags of ammo through the gun, and cleaned it for me. I took my wallet out and asked, what I owed, she said, "nothing, thank you for stopping in and allowing us to service your firearm.

Check the rear sight? Mine came loose once.

https://www.ar15.com/forums/handguns/Comprehensive-thread-of-Dual-Use-Magazines/4-200117/