I also don't get why everyone is so blown away by the visuals. Maybe some painfully slow deep space docking maneuvers would have been a sight to behold in a pre-Gravity era of cinema, but I'm not really sure about that either. Cool robots, though.
Hard to describe really. I put it down to Christopher Nolans sense of how he directs his movies. There wasn't that much action in the movie, but the way it was filmed, it really managed to create the tension other movies just fail to pull off. That scene with the spinning station was out of this world IMO and completely blew me away. The visuals as such, as well as the sound/music were a standout feature for me. I left the cinema feeling as if I was part and witnessed something of epic proportions. To be honest, I can't remember feeling that way after watching a movie for a long time, if ever.
I can appreciate the fact though that this movie isn't for anyone, even science fiction fans.