Downloaded first thing this morning (update was running a little behind for North America and I forgot all about my EUR account) and really, really dig it. Completely overhauled physics engine and the cockpit view is amazing. Finally some gyration and bumpiness while viewing things from inside the car.
I heard a lot of talk about Forza being the most realistic driving simulation a few months back and I had to bite my tongue because, well, I'm not privy to playing Forza. However, this new GT5 build blew me away as far as a simulation model is concerned. I've gotten fairly good at GT5: Prologue, but my skills didn't quite help me with this new engine; I was a full eight seconds off of the leader in the tuned car!
The graphics left a bit to be desired, but that's probably more to do with the track than anything. Bland to say the least, but Prologue alone shows Polyphony is up to the challenge from a visuals standpoint. Not that graphics are close to everything, but Polyphony set the bar high long ago and... GT5 with lackluster visuals would be just as heartbreaking if Square shipped FFXIII with Modern Warfare 2 grade cutscenes. "Disappointment" says it all.
Custom soundtracks would put this game over the top for me. I'm not above wearing headphones, blasting my custom Nine Inch Nails driving mix via the PSP. But it would be so much better if my neighbors were forced into submission by lossless, deafening 5.1 audio, Mr. Reznor screaming "I'M GONNA BURN THIS WHOLE WORLD DOOOWWWNNNN!!!", the industrial sound of NIN blending perfectly with the roars of engines and shrieks of tires.

