I just bought one recently and have been too busy with work and kids to go shoot it. I am pretty amazed at how easy it is to break down. I never had any real trouble with the MkII or MkIII but this is a nice system.

What do you put on all the rail space? Red dots, lights, lasers? What suppressor do you like to run on it?

Not a damn thing, took them off as a matter of fact

I have no need or desire for a light or laser on this pistol. I may add a red dot at some point but probably won't use the factory rail if I do?

Dead Air Mask HD

So before you ask why I bought the tactical if I didn't want/need the rails... I already had a MKIII Lite and wanted an MKIV (for the easier takedown) but decided I wanted to try the steel upper version just for something different and to see which one I liked better?

I was looking at a new 22/45’s and went with a Black 22/45 Lite.
I changed out the grips and installed a Volquartsen accurizing kit.
I took the top rail off and i don’t like looks of rails on the little 22’s.
If i do a red dot I will take off the back sight and use a Burris 3 mount and optic.

Bought my Mark IV before the tactical was available.  Had the barrel cut and threaded.  I don’t have a need for optics or a light on a 22, so the rails on a tactical are meh to me.  But a set of Williams fire sights are in the works.  I will second the Dead Air Mask HD.

Nice looking pistol.  What kind of grips are those?

Stoner CNC.  My biggest complaint with the Mark IV is the standard grips feel cheap.  These feel quality, and are VERY grippy.

I just picked one up yesterday. I swapped out the front sight with a fiber optic one from TruGlo and added a TLR-1 light and my Spectre II. Eventually I want to add a red dot to it…

I like it, I like it a lot. I have several thousands of rounds through it since getting it about 6 months ago and I can count the number of malfunctions on one hand. I lubed it up with Cherryz Rimfire Remedy and just ran the hell out of it. When I finally took it down recently for cleaning it was completely dry but still running just fine.  I got a knock-off C-More red dot for it and makes for a fun little plinker. I don't plan on using the rail under the barrel. It runs great with my Rugged Oculus. Plenty accurate.

I took the red dot off to practice using irons more. I do need to upgrade the front sight to fiber optic and something a little thinner. The factory one is wide and I have a hard time with it. Plan on upgrading the trigger eventually.

Great gun. Its got some weight to it, especially with the Oculus. I would like to try out a lite version to compare but I did want the heavier version. Perfect to introducing new people to shooting.

Wish someone would figure out how to make higher capacity mags for it though.

The other day I got out my MkIII version to compare. I got the one (MkIII 22/45) with the top and bottom rails but, no iron sights. That one requires a dot sight of some kind. I have a little Bushnell TRS-25 on it and while it's definitely bigger than a Burris Fastfire, it's still small enough not to be unreasonable. I moved my Fastfire to the MkIV. I definitely like the safety and bolt release controls better on the MkIV and really like that the stupid loaded chamber indicator is gone. I miss the Ruger emblem they used to engrave on the back of the bolts in the MkIIs. I'd hoped that would be back for the MkIV. I don't really understand why they had to change the magazine base plates but I found a place on ebay that sells the MkIV base plates which are backwards compatible with the MkIII (but the MkIII plates don't fit the MkIV). It looks like the internal safety lock from the MkIII is gone as well, and the magazine ejector spring is a nice touch as well.

All in all I think the MkIV is a well thought out evolution of the design. The changes are more significant than I expected. Takedown is much easier, but I learned on a MkII and it's really a breeze so that was never a deterrent for me. The real deciding factor in purchasing a MkIV for me was the rails with iron sights included and the LCI gone. The new controls are a nice unexpected bonus.

Very pleased with the MKIV, I took off the lower rail, got some filler screws from Ruger. Top rail was longer than I need, so replaced with a shorter aftermarket then added the small red dot to help with my aging eyes. Also added a halo charging ring, it isn't necessary, but I like the ease of manipulating the slide with that ring. Put a suppressor on the end, and pop cans are in serious danger.