What was an oustanding 3D cinema exeperience is only a good 2D Blu-ray. With very little in the way of plot and characters, this is very much a film of special effects and raw emotion.
With a resonable main baddie, and CGI good enough to convey the expressions of the other characters, it just about manages to maintain your interest for its bloated duration.
Aside from the fantastic 3D experience, and envelope pushing effects, this is very much a retread of Cameron's previous efforts - think a goreless Aliens with the romance of Titanic, and you have a reasonable idea what to expect.
This really isn't worth getting until they release a 3D version that rivals the quality of the cinema, and I wish he hadn't opened his eyes at the end.