I agree with scoobes, those changes would iron out what is probably the best feeling battle system in any Final Fantasy. The difficulty is also shockingly high for a series western reviewers were worried was getting easier and easier with each iteration a few years ago.
It can be really fucking frustrating, especially the summon battles which have pretty much always taken me at least three tries (and sometimes as many as ten.) But after getting your butt kicked in a really hard battle, you remember how many different ways you have to manipulate fighting conditions before the battle begins -- by getting a preemptive strike, by using the items that buff you before a battle, or by equipping weapons and accessories specially tailored to a given battle (or changing your party for certain parts of the game.)
FFXIII forces you to utilize every aspect of the game in order to get through, which is definitely the most challenging experience I can remember in an FF.
Overall, I would say it's a great battle system that still manages to have plenty of its own flaws, but at least one of them isn't sitting around being bored while you win every fight.
I still prefer Grandia's system though -- there's so much thought that goes into interrupting enemies in those games, whereas in FFXIII it feels mostly random.
I'd also say the Tales battle system edges it out for me, but only because it has a multiplayer option.
