MC3 is a wholly different game than MC2. It's far easier to beat the AI. The races hardly increase in difficulty at all as you progress through the game. I wish it had been more difficult, because I loved MC2 but I finished MC3 in no time - and I don't consider myself a very skilled gamer at all. And now, well, um, I guess I could customize all my cars again, but then what?
There are a lot of races, but they get rather repititive. Varying traffic, levels of difficulty, and other factors made the races in MC2 more interesting.
Perhaps the game is more interesting when played online, but I'm not much of an online player. I like to chill out with a challenging and interesting game, but MC3 doesn't last long enough and is not really challenging enough to satisfy. Perhaps Rockstar should have created some interesting characters to match the customized cars.
The industrial wasteland of Detroit in this game is great, but Atlanta and San Diego look almost identical. The soundtrack has some good tracks, such as NIN, but otherwise for the most part the soundtrack blows.