As I said multiple times by now, that trade off will always exist on consoles since they can't be upgraded (1) and have worse hardware than PCs at their release date (2). All games, and I mean all, run better on their PC counterpart (dev-only or port) no matter if it is a new console.
1.- On pc games/sims the devs can put an option for 64 cars dx20 if they want to, since they know people have different pc specs. That can't happen on consoles, so in order to prioritize they are forced to leave it at 16 for example and can't go above that since consoles can't be upgraded (for the most part).
2.- Consoles have an inherit limit that PCs don't have as much, or in other words they have better hardware, which is why the dev versions of games are made to fit into consoles (bo2 textures on the 360 is a top notch example) and why doing a hd re-release is pretty easy for games released on the previous gen.
For example there are uncompressed textures, fully detailed models (to put it that way), more resolution (gt5 does not run at 1080p and we know gt5 can run at 4k np), more and steady fps (gt5 does not run at steady 60fps and someone at the office must be playing it at 120), better effects, better shadows and lightning, different engine, more already made features that couldn't be put on the ps3 version due to ram and general hardware issues, etc. etc.
Lets put it this way: I'm 100% sure the mind blowing "photomode versions" of GT5 cars are not even comparable to what those models look like on the PC version of GT5, and as we know premium models are the best part of content quality-wise on GT5.