I braved the elements to go see this in 3D. I thought it was good, better than I expected actually. Pretty formulaic as far as narratives go, but sometimes that's alright. The main selling point, and rightly so, are the visuals. As I said, I watched it in 3D and it was a real spectacle. It's not as brash as having things fly in front of your face all the time, it's rather subtle until it reaches the point where it almost becomes second nature.
Before I went to see it I was thinking a 5/10, but now it seems like an 8. If, like me, you have your doubts about it beforehand, just give it a chance and you might be pleasantly surprised.