PGR3 is merely a track racing game with a few dents and dings thrown in for effect.
It is a great arcade style racer with no storylines or plots. It is simply a plug and play game that rewards you with trophies and acheivements for playing longer. That's it. The graphics are pretty amazing, ( have only had the 360 for a week). And I say that they are amazing because it's hooked up to my 15 year old sears tv in the rec room.
In terms of gameplay. I have played nearly every racer for the xbox, ps2 and ps1, as well as the old n65, nes, snes, etc...
By far, the best racing game is forza. I cannot wait until Forza 2 comes out. PGR series of games are good games. They have better than most graphics. They have simplistic cars ( no kits, turbochargers or NOS to worry about). The soundtracks have always been decent.
I can go on and on about a pile of xbox racers... largely because I pretty much sold them all yesterday. :) No use, never played them anymore... I ended up dumping about 32 xbox games yesterday. Got myself some nice shiny new 360 games... :)