I beat the game at about 70% completion and haven't really been motivated to go for 100%. The lack of AA/AF on the XBOX version rapes my eyes to the point where I get that stinging sensation whenever I close them; and the issue with vehicles disappearing from your garages (known/acknowledged bug) really annoys someone like me who is OCD about what they drive; also the driving, while fun at first, quickly gets boring due to its lack of depth. I might give it another shot after Rock* releases their first patch if I can get my dirty mitts on the PS3 version but I'm not really feeling it right now. (I only played the XBOX version because a friend practically forced it on me.)
These issues aside, it was a decent story.