My problem now is I have been playing with my friends over doing my own quests, and they are about level 24 or so. The good part is I went from level 12 to 20 really fast, but now all my quests are trivial and not worth anything.
So I might just burn through the story missions and forget about the side quests until my next go around.
Game is great though, been hitting the slot machines pretty regularly. All my friends are doing all the hacks, which I have never been really one to do. However I did let my friend give me a million bucks, just for some walking around money.