It is a better rifle, accepts optics better, and is more accurate. It handles heat better. It is just a better rifle.
I completely disagree. With the DSA mounts available I think the FAL accepts optics way better than the PTR. The PTR can be more accurate, but thats it's only strength.
The PTR is made of stamped steel, has no last shot bolt hold open, the safety is out of reach for most without changing your grip, the magazine release is probably one of the least conveniently placed that I know of, the charging handle is heavy and also inconveniently placed, they have the worst triggers ever (but that can be fixed for around $70). Optics mouting options are a claw mount which puts the scope very high over the bore, or low profile mounts which just don't seem sturdy (maybe superstition on my part). The PTR also seemed to be the hardest recoiling and had the most muzzle climb of any autoloading .308 I've handled (but I realize that is mostly subjective). And it waffles, dents and hurls brass like no other (at least it hurls it all in the same direction, unlike the Mini-14)
The STG58 is forged, has last shot bolt hold open, the safety is every bit as easy to reach as on an AR15, as is the magazine release. The charging handle is possibly the most conveniently placed on any autoloader I've used (I realize that is just opinion) the trigger is nothing special but worlds better than the PTR, DSA makes great mounts for optics, and the adjustable gas system lets you reliably use a wider variety of ammo (especially very light loads which may not cycle in other battle rifles, not something I have experience with, I just shoot 150 gr. surplus, but there was an article I read a while back about how the FAL was much more reliable with 110 gr rounds than other autoloaders due to the adjustable gas system) and it lets you tune the rifle to the ammo to reduce recoil and reduce wear on the rifle.
I had a PTR for a while, tried very hard to like it, decided I would always hate it and sold it for a beater of a FAL and a small profit, and am much happier than I ever was with the PTR.