SO I have had some experience with FNX45s and have swore off them. Occasionally I do hear their siren call at the gun shop, but they are just poorly designed. Yes, I said it.
The entire reason the FNX exists is mired on controversy. The FNP had so many problems that FN had to redesign the pistol and name it the FNX. However, FN gave the shaft to all the FNP owners by not honoring any warranty work on guns that are known to be faulty.
Even the current FNX is not without problems. It is far too finicky with ammo fr a $1000, supposedly combat handgun. The polymer used is known to go very,very soft in heat to the point where some have reported being able to make indents with your fingernail. Mags don't always drop free, even loaded. The do any sort of maintenance to the pistol that requires disassembly requires you to break some pins, essentially breaking the pistol.
I REALLY want to love that gun. 15 round .45? hell yeah....but I have owned two std FNX45s and one tactical. I have had mag release/drop free problems with all of them. The Tactical did have extremely soft polymer, not nail-indent soft but just squeezing it with a strong grip made the pistol frame flex noticeably. None of mine would reliable feed WWB or Federal aluminum.
Go to the FN forums...you will see that those guys put HK snobbery to shame. They will make fun of you for putting 87 in your Ferrari by using WWB in your FNX-T while not addressing the fact that a combat handgun can't feed stuff that even a hi-point could.
I'm sorry if it sounds like I'm shitting in your cheerios, that really isn't my intention. That gun pisses me off so bad because I want to LOVE it so freaking bad but it just let me down, 3 times. My old Tisas POS beat to hell 1911 was more reliable.
All of this,however, is just my opinion and experience. YMMV
