I own 11 of them still. 10 are unfired, one sleeps by my bed at night.
The 10 were leftovers from when I closed my shop. I accepted the order instead of taking a restock hit. I'm holding on to them to see what happens in O's second term.
I've shot 5,700 rounds now through the PS90 and FN Five Seven (that's the exact count of ammo I've gone through, but I have no idea how that splits between the rifle and pistol). The majority of those rounds have gone down the PS90 barrel.
Some of the facts...
I have never experienced a single failure to feed or fire.
Generation 1 PS90 optics are junk. (The white "donut of death" reticle). It's impossible to use in low light and if you're shooting at white paper targets you can't get any idea of where you are aiming.
Generation 2 PS90 optics kick all sorts of ass. They are labelled as "RE" versions. The reticle is a crosshair configuration, but in low light, the thing glows red. It's really sweet.
Then you have Tri-Rail configuration, which features a MIL-STD 1913 rail on top and two smaller ones on the sides. These have no integral sights, you must add an optics system of your choosing (EOtech, Aimpoint, etc).
One of the neat features is the downward ejection of brass. You can buy a clip-on baggie (FNH or aftermarket) that the gun is designed to accept. All of your brass falls in the baggie when you shoot. So you can unclip it and dump your empties - they never touch the ground.
They also feature a dust-cover in that ejection port, which you can snap shut to keep any grit or crud from getting in to your action. This is opened automatically when the action is worked manually or by firing a round, and remains open until closed again by hand. It creates a great seal to keep any dust, sand, or dirt out of the mechanism.
Obviously the 50 round capacity is a huge boon.
The ammunition, weapon, and magazines are fantastically lightweight, even with the stock 16" barrel.
It's accurate enough to hit 6" targets reliably at 200 yards with the non-magnifying reticle sights.
The SS197 ammunition (which is loaded with 40gr Hornaday V-Max) leaves the PS90 at something around 2200 FPS - and hits with a significant amount of disruption. The jackets are thin and the round pretty much disintegrates in to small fragments on impact.
They do not penetrate deeply - just under 10" (corrected) in most penetration testing with denim or bare gelatin. This should be considered a potential drawback as most sources consider 12" penetration or deeper to be required for effective defense. Or, it could be viewed as a positive if you live in an apartment, or have pets/family that you are concerned with.
Ammunition is also commercially available through other sources (check FiveSevenForums.com), with different characteristics than the FNH factory ammunition.
Ammunition used to cost less (all ammo did), and is currently hovering around $21 a box/50 rounds (0.42c each).
Reloading the 5.7x28mm is a bit complex, I haven't gone there yet, but plan to. If you plan on reloading do yourself favor and do a lot of homework!
In terms of practical real-world, non-anecdotal effects, the 5.7 has been shown to be a devastating cartridge. I won't cite a source here -
most people here will know what grim incident I am referring to, and it's best if we don't discuss it. It's sufficient to say that I have no doubts whatsoever, on whether it can be used as an effective self-defense round.
Any other questions?