I was actually ok with the battle system, and definitely enjoyed it more than most of the "haters" out there. XII's was better, but I was still entertained by XIII's, and some of the tougher battles were memorable. But I would still consider myself on the hater side, as the rest of FFXIII was pretty terrible. The game was very sloppily put together after all the time spent on graphics, and some aspects seem like complete after-thoughts (weapons upgrades, and hell, even the entire gil system. IIRC, there's literally one grindspot to get any significant amount of gil until the end of chapter 11, when you can get a troutton from a chest). The Crystarium was bland, the linearity reached almost parody levels, and the story after chapter 9 was brutally bad. "Oops, we forgot to figure out how the story unfolds after we got everyone together... well, let's just have the bad guy tell us everything like a bad action movie." I also did my best to block the entire chapter 10 from my memory.

Unlike the haters, I thought it was ok to play through once. The beginning of chapter 11 was actually enjoyable, for instance. But like the haters, I can't imagine voluntarily playing through it again.