It fixes all the problems the first had, and delivers an even greater experience
However, it was plagued with flaws entwined with the basic fabric of the game: the creature "education", though great, had to be unveiled by watching closely, while losing detail of the rest of the things happening in the world. The camera control had some serious issues as well, so getting from place A to place B at the other side of the island could be a real nightmare.
B&W2 fixes these issues by placing education stats (resolving the first issue), and making a great improvement over the mouse control of the game. It also introduces new buildings and new side quests, all of them really interesting.
The only bad thing I can say about it is that it sometimes becomes a bit frustrating to need to restart a scenario in which you had already spent 1 or 2 hours, because you realize there's no way to pacifically resolve it (i.e. there's no way you'll get that much influence with what's left on the island). For those who prefer the darker side of the game, though, this isn't probably an issue!