It's fun while it lasts but you can pretty much max out your level in a long weekend, and there isn't very much to do. There's also a significant lack of players on their "super servers", which you may or may not feel depending on your hours. In CO, finding people is easy as **** and they're usually really nice and helpful. Then again, my first MMO was City of Heroes, so it would stand to reason I'm a little more inclined to favor CO over other superhero games.