Quote Originally Posted by Flamethrower
The beginning of the Geno Dome where you have about six or seven consecutive battles is a great way of leveling up, since you can just jump down the dust shoot and do it over again. However, if you have already defeated the mother brain, you can't re-enter.
The only thing I can do is concur with this statement. I did the majority of my leveling in the latter half of the game at the start of the Geno Dome. It's a great place to develop your party. The fighting isn't too difficult, and the experience is good. On top of that, you can get into one of those leveling cycles, or routines, where you can do it for long periods of time.