I've only just got to Meridian so I'm not very far in, but so far I've been highly impressed with how well paced this game is. It's a huge open world game that rattles along with the pace of a linear action-adventure. Even when you wander off to explore and mess around in the environment you still feel that there's purpose and direction to it. Nothing so far has been at all slow, or boring, it never seems to drag at all.
I've seen some criticisms that it borrows too much from other open world games, and while those mechanics are in there, they feel streamlined and minor - just supporting structures to what the game is really about: combat and story (including the fantastic setting). This is just a really fun game to play. So much so that I don't even mind dying, or redoing things. Each combat situation can pan out in all sorts of ways, it's all beautifully dynamic and satisfying. I hope there's an NG+, and if not, then I hope they add one.