Went today to get on a list for the FN 5.7 and the FNX 45 Tactical.  While there I picked up an FNX 9.  

Range time this weekend

I picked up a used one a week or two back.   For what I gave for it, it was a no brainer and I think it's a solid enough gun.  

Put about 100 rounds through it one afternoon.   Seemed accurate enough (i.e. not any worse than a Glock or M&P), and ran fine with my handloads.  The DA trigger is awful like it is on most DA / SA guns, but I plan to pretend that it doesn't even exist.

I like the fact that the white dot on the front sight is visibly larger than the rear dots.  I also liked the ambi mag release button.   The slide is wider than any common competitor's slide, which may give it a blocky feel in IWB holsters.   The backstrap retention mechanism seems a bit dinky (a flimsy plastic tab inside the grip) but I guess time will tell whether that's a problem.

Your right about the retension system.  I was surprised when I saw that great engineering feat. A little,movement in the blackstrap. I'll fix that

Let me explain how much I love my FNX9... I sold my Glock 19 after firing the FNX.  I just wish i could find night sights in stock for it. I can put all 17 rounds in the X ring at 10 yards something I could never do with my G19

I have just over 1300 rounds through mine.

Never a hiccup of any kind with anything from 115 Wally World Federal FMJ to 147 grain HSTs.

I too like that big dot on the front sight.  My 58 year old eyes like it even more...  

As I intend to keep this one, a single drop of "super glue" fixed the loose back strap issue.  Some may remember my posts at FN Forum, as I tried several mechanical fixes for the dinky retention tang.  
None were satisfactory.

I like it's "commander-ish" size really well.  Slide length like a G19 with 17 rounds in the mag.

The trigger pull has settled in to 4.25 lbs. in single action.

I am hankering for a Walther PPQ, but the FNX will be a permanent member of my collection.

Love mine.  Ambidextrous controls are great, as a southpaw.  
I just wish there were more accessories for it

DSG Arms makes great holsters for it. Raven makes them also but the wait time on them is crazy.

No recoil
nice SA trigger


just watch that you don't ride the safety like a 1911.