Difference between PS3 and P4 is huge. The frame rate is stable, the loading times are short. The only issues you might notice are hunts and odin/behemoth as others said. Thing is that it kills v. good PCs of my buddies as well, the S hunt disappearing is issue with code from devs, not your machine i believe - was same with Odin/Behemoth before they fixed it.

Visuals are great, my eyes were like O_O after I switched from Ps3