Gravity wasn't big on plot or storyline and had it's fair share of mistakes and farfetchedness. But the movie wasn't about stories, it was an experience movie. And it nailed it very very well. And the use of 3D was very well done and didn't seemed forced (Desolation of smaug was ruined by forced 3D).
Gravity was a good entertainer with stunning visuals and proper use of 3D, and I wish I could've watched it in IMAX.
Also, are there any decent sci-fi movies that one can think of from recent times apart from Moon? Probably not and Gravity probably comes quite close to being decent sci-fi and not the gun and violence crazed bullshit like Pacific Rim that is fed to us in the name of sci-fi.