Either way whether it looks better or not I'm pretty much sure that GT5 will be the best (or perhaps most comprehensive) racing game ever created - Polyphony are masters (and perhaps the founders) of this type of game and Yamaguchi is a perfectionist to the levels of Miyamoto or Sakurai or Kojima.
I feel as that Yamaguchi is doing the same sort of thing as Sakurai is doing with Smash Bros - leaving no stone un-turned and nothing not included in the game, it will be the definitively absolutely ultimate Gran Turismo racing game.
All that said so that I can simply say - GT5 will outsell PGR4 no matter what.








