I've only just got a PS3 and GT5 in November (waited for GT6 for Xmas
)
The physics are not great compared to PC sims, but that is not the reason for me. For petrol heads who like cars, it's great to look through all the available exotica (or cars you've owned) and plan your next purchase.
And it looks great! The progression through the levels is enjoyable enough, I haven't played online yet.
I got my PS3 second hand from CEX (in UK), it's kept me entertained while we wait for the next LFS update.
Just don't expect to be blown away by the physics