I have not seen it but I heard good thing about 2 plus I hear it ended as a clif hanger so I imagine they will do the same thing with 3 and 4. We have no big epics coming out anymore, no LOTR so we need something.
#2 was awesome, but its a movie you should really see on the big screen first like any epic movie. Or wait for the DVD if you have a very large TV or a personal theatre.