I haven't had it for long, but I like mine a lot. When compared to my Greek SAR-8 it is a very nice "copy."
As for the Parts count, there are normally 20 parts, but the PTR-91 series only has 17 of them, or 16 if there is no muzzle device.
The parts are:
(1) receiver
(2) Barrel
(3) Mounting blocks (trunions)
(4) Muzzle attachments
(5) Bolt
(6) Bolt carrier
(7) Cocking handle
(8) Trigger housing
(9) Trigger
(10) Hammer
(11) Sear
(12) Butt stock
(13) Pistol grip
(14) Forearm
(15) Magazine body
(16) Magazine Follower
(17) Magazine Floor plate
On the PTR-91, the barrel, receiver, trunion, cocking handle, pistol grip, forearm and buttstock are US made (at least on mine they are.) That leaves 10 german made parts to keep in compliance with 922(r). If you replace the furniture with German made parts, you'll need to add other US made parts to get the foreign count back down to 10.
If you buy a Thermold mag and keep it in the gun, that is 3 American parts right there, or you can get a US made trigger, hammer, sear, etc. to correct th parts count.