The camera is the only thing that really bothered me so far. In confined spaces it always gets stuck in an annoying corner.
So far I've only had two fights that gave me any trouble. The first being the end boss of chapter III.
The second is not long after that, early in chapter IV, where I am faced with the Wild Hunt. I was pretty stupid in replacing my blue silver rune sword with a red silver rune sword. The red one has a good chance of blinding or incinerating enemies, but that's not useful against many types. The blue sword had 50% more damage and that was really noticeable. With the right oils on it I was dishing out nearly 200 damage per hit in strong mode at lvl 27.
The problem is that rune swords can't be bought back. The three blue runes I spent are forever lost, so now I can't get it back. I think I'll use a Witcher save game editor to replace my red sword with the blue one again.