Just picked it up at Fry's, passed it up yesterday, don't know why. There were only just a couple of scenes that were grainy, but then it would switch immediately back to great quality. Must be just certain "shots". But overall HD quality is very good, some striking face detail on closeups, very colorful. And 3D was among the top tier as far as demo 3D.
This movie is basically a 3D spectacle. There is no reason to ever watch this movie in 2D. It was made as sort of a "amusement park" type spectacle. I mean it's got a 3D mine cart ride in it if you need any further proof.
Anyway, when RealD 3D first started coming to theaters I was excited, and this was the very first 3D movie I ever saw in theaters so I had some nostalgia for it. the 3D bluray does not dissapoint. Great 3D depth, a good amount of in your face gimmick shots, and just sort of a fun "ride" type movie. Don't hesitate if you just want to experience some great 3D. It is very fun as long as it is being watched in 3D.