Now I haven't finished the game yet, but what is annoying from the start is the camera, if you pull it up and away (to an rts kind of view), I am not able to move it as far as enemies have missles/magic range. So an enemy might shoot at me and I have to zoom in and find the enemy, which is 50:50 that I can even see it from some branch or something getting in the way...that was the most annoying part.
Another thing that made things difficult - often, if I overlooked a character for a second, it would cast a spell/attack that just wasn't right for the situation and would be more effective in another sequence but if I clicked on it - it would not be used but was spent and had to recharge - what the hell!?
Also the specialty (shapeshifter, paladin etc.), I had points that I couldn't use, for example Morgana was the teacher but even if my realtion was peeked, she still wouldn't teach me shape shifting. On that note, changing companion so when I do run into some character I don't lose realtionship points is kinda annoying...although "realistic" sort of.
As mentioned - difficulty spikes. Lots of battle results come out of sheer luck and more than once I was running around so my mana charges up, because as a mage I'm pretty much f-ed without it. Sometimes I could lure enemies into a tight spot (like a doorway), put a rouge and warrior to hold them off while I do my spellcasting...except that the bloody AI is hard to control as hell.