I'm leveling up pretty quickly in Crackdown. I've got 3 stars on agility, 1 on driving (haven't worked on it a lot), 2 on explosives, 3 on strength, and 2 on firearms. All that, and I just dispatched the first Volk gang. I do wish there was a little more depth to the game overall, but defeating the gangs are pretty much the same. Decide whether you want to level up firearms, strength, or explosives, then proceed to kill all enemies with that tactic. I've gotten my strength up so high so quickly because I decided to just kill every enemy in a couple of Los Muertos gang spots using hand-to-hand combat.