Damn, I'm about 34 hours in and the boss fights are becoming properly hard now.
My only gripe with the game so far is the lack of battle setting you can set the AI to ala Final Fantasy XII. Your team mates can be properly brain dead most times and you can't rapidly switch between them to make them do what you want. This causes you to become frustrated not at the difficulty of the boss fight (which can be bloody tough) but at the idiotic things the AI does, which ends up getting them killed.
The battle system could have greatly benefited from the
Gambit system that FFXII used. As it stands you can only set them to very rudimentary (and undescriptive) tactics, that makes very little difference during fights.
Add to this the fact that the game doesn't pause when flipping through skills meaning you end up fumbling trough the list trying to hit "Defend" when the boss is about to perform a big move only to miss the opportunity because you took too long to find it, so you end up taking full damage.
All these little frustrations hurt the overall combat quite a bit IMHO and as much as I love the game, this is definitely my one major sore point. I'm having to grind levels so that I can brute force my way through fights, rather than win via smart tactics.
It's also annoying not being able to see your teammates mana levels while fighting, so you have to either switch to them or use an item in order to see it. Lots of little things that seem to have been overlooked when it comes to this aspect of the game.