It wasn't obsessed with momentum at the expense of everything else.
Gravity's story unfolds simply, as a series of action rushes interspersed with more peaceful and introspective moments. It's striking how few action films these days allow themselves that kind of "breath" in the proceedings, and it's striking how much more forceful and gut-wrenching the action sequences become by contrast. It also has other benefits, like providing the time for Bullock's incredible performance to flesh out a satisfying character and her arc; and giving us leisure to really feel the vastness and power (and terror) of the setting.
Because the director isn't constantly trying to compress any sense of time and distance out of the narrative, Gravity's little region of orbital space feels in some ways far larger, and its stakes higher, than the planet-smashing settings in Man of Steel or the "galactic" setting of the Trek reboots -- I've never felt more vividly immersed in a character's terror, and the possibility of horrible death that attends the slightest mistake in space, than when Bullock's Dr. Stone is sent spinning out alone into space in the movie's first action sequence.
It wasn't self-consciously trying to play up a style of camp, kitsch or schlock.
As one of a small club of Hollywood films today which isn't trying to exploit nostalgia, Gravity was free of the temptation to "cleverly" camp anything up. The result was a straightforward, riveting story of survival which had a coherent narrative, logically consistent science and technology, likeable characters who are believable in their respective roles, no need for a leering villain or save-the-planet stakes, and no need (indeed no room) for obligatory romance. The action, and the fun, was all the better for it... something it would be nice to see more SF properties embrace.
It wasn't trying to pummel my senses into submission.
The effects were amazing, but they served the story. I didn't get the sense that the director was trying to deafen or numb me with frenetic effects shots and explosions -- something too many action movies are currently prone to do in an apparent effort to keep the viewer distracted from shoddy plots.