Saw this movie in 3D at a MUVICO theatre with a Sony 4k projection. There wasn't an over the top use of 3D. The use of 3D provided depth. Seeing this movie in 3D is a must for those who are movie buffs but for an average viewer, like my wife, non 3D would be better.
Without giving away any spoilers, the story and plot were very predictable and sorta cliche-ish. The world he created had elements from his undersea diving adventures between the making of Titanic and Avatar.
Overall, this is definitely a movie to be seen, for the first time, in a movie theater and not on a home theater screen. There is just so much to consume from the vast world that James Cameron created that a small screen just won't give you the same experience.