IMHO, the PTRs have more of a cult following than any hugely clear advantage over other rifles that I see.
Running one is training, I don't have an issue changing between rifles. If you practice handling the rifle, the controls are pretty easy to learn.
+1 to both of those points. They are good solid rifles, but there's no confusing them with a lightweight carbine.
Mine was the PTR 91 GI model, 18" barrel. It shot well (1.5-2 moa) with 165/168gr bullets, but for some reason did not shoot any 150gr bullets well. I welded a rail for scope mounting on mine; you can send it to several places to have that done, or buy the newer PTR model with the rail already installed.
The triggers can be cleaned up to get rid of the creep, but it's hard to lighten them very much.
