It's one of those MMO's (Yes, it's an MMO... even though everyone on their forums class it as something else) which promise so much but deliver nothing.
There is very little in terms of gameplay. The worlds are incredibly small. There are about 4 types of missions.... as the Enforcers it's simply 'Collect these cars' or 'stop these players' while criminals don't really differ. They both feel the same near enough.
The customisation is really good, but thats about all their is in this game thats got some depth. The rest is just a rince repeat of the same missions over and over on a very, VERY small world.
It's using the Unreal 3 engine which is pretty amazing seeing as how bad the game runs. Driving is chopping and messy and at high speed you need a pretty decent computer to keep up with the spikes. Rubber-banding is also an issue but thats server side.
Overall i wouldn't both with it. I played the closed beta solid for a week and acomplished nearly everything i could within 3-4 days to my shock.
My advice. Boot up your 360 or PS3, load GTA4 and play the same game, with more options, for free.