I would actually beg to differ from "painfully short". The movie sacrificed some things for other things, but that is what all movies do. Gravity only has two characters (effectively), and the movie is emphasizing the silence and vast loneliness of space. It's that backdrop upon which any dialogue is laid and framed, and I found it to be excellent at packing a lot of information in a limited number of lines. Anything extraneous was jettisoned (after all, in orbit all space is at a premium). I didn't need to have a lot of interaction between Clooney and Bullock to know exactly who they were as people and what they represented; more prose and interaction would have distracted from the tone, mood, and pace of the movie. The limited dialogue contained a lot behind the scenes (emotionally) if you unpacked them.
From a personal perspective, I especially connected with Bullock's character, framed against the recent loss of my father, and the same perpetual dilemma a human being faces in the face of grief and how one either decides to continue to live or perpetuates instead a living kind of death. My dad died forty years ago or more, despite remaining alive; I made a different choice; the characters here also have to wrestle directly with how to approach their own lives (and possibly deaths). Also events in the past year or two of my life left me identifying with basically hanging on by your fingernails, springing from one solution to the next and somehow getting out of one scrape to feel backed into a corner almost immediately.... and how sometimes it leaves you just wanting to give up. The whole movie was one harrowing leap from frying pan to fire and back into a new pan.
But I really agree that the set pieces and backdrop was just awe-inspiring, constantly taking my breath away. I have no idea how they filmed that or recreated what that experience would be like; it felt very real to me, like I was there. And in the IMAX 3D setting, the empty space looked very vast and frightening, and the shots of earth filling up much of the backdrop were just glorious. To me the movie was worth seeing just to feel like I was actually there in orbit experiencing the grandeur of space.