I actually enjoyed the battle system and the huge character roster. They took a lot of getting used to, but they were just such a break from what most of the other JRPGs I'd been playing did (the largely element-based system, the four-person party, etc), and I liked going back in the New Game+ and finding the characters and subplots I'd missed the first time around. It gave it a lot of replay value for me.

I can see how it wouldn't be for everyone, though. Going back now that I'm used to more streamlined systems that still manage to be different, it would probably frustrate me too.