Started playing this yesterday, was okay. Made it to level 6 in a single evening, doing only multiplayer races. The problem with MP races is that everyone tries to ram you if you pass them, and if they time it they can send you into the wall and you fall to last place. Throw huge gobs of lag in all of that, and you get Frustrato9000: Racing Edition!
Mostly, I like it because I haven't played a NFS game since Carbon, and I played Most Wanted for hours and hours.
Currently I have the Mazda Tier 1 car (which is better than all the others, even the Nissan, though some on the official forums think otherwise) with the "Street" upgrade. Woo!