The story is pretty solid, though the execution could be a little better (as someone else already mentioned).
Really, Larian got so much right I feel like I'm nitpicking things. And there are things to nitpick. But it's a big beautiful game with a solid story for 90% of the gameplay.

And some of the individual character writing is really great. I mean, whoever wrote Magister Loke? You jerks almost made me cry.