I've had it since the APK was ripped from the Droid X and posted. I paid $9.99 to unlock it, though (the price of being an early adopter).
It's pretty close to the console version gameplay-wise. And as far as racing games on the Droid, i'd rate it as one of the best. However, Gameloft is supposed to be releasing GT Racing: Motor Academy any day now, so that game might take the crown (especially if you are into sim racers, NFS is more of an arcade game)
Definitely worth $4.99, though. That's a fraction of the price of any other version of the game. And it's just as much fun to play.