I played on it for a couple hours, and I must say this game makes GTA look like shit. The cars are awesome slightly unrealistic, but it just adds to the fun level. Things such as hitting random civilians with a bat is much more funner because the cops dont show up out of nowhere, and when they do you can beat the crap out of them with the bat.
You can also go around hitting other gang memebrs and when they call their crew just beat them up with a fire hydrant(something you can get in GTA) You can remove sign posts and fight with them. Missions are also pretty fun to do unlike GTA.
Many fun activities when you're bored like spraying crap on houses or pretending to be a cop and alot more I havent tried.
The only thing I regret is that I wasted $65 on GTA IV, instead I could have bought a game with the same features and more.