Great movie, I really enjoyed it. Incredible cinematography.
But... if you know anything about space travel you have to suspend a bit of disbelief.
1. Comm sats orbit at 22,000 miles. They wouldn't have been affected by the cascade which was taking place at around 380 miles, or at least not as quickly as portrayed in the movie.
2. No way in hell they're going from the Hubble to the ISS, and to the Chinese stations all of which are in different orbits and inclinations with only a backpack and no navigation.
3. Astronauts wear a suit under the space suit (the LCVG) that regulates body temperature and moisture. They also wear a large diaper to pee in. Sandra Bullock wouldn't have come right out into her skivvies. Okay, so I can forgive that artistic license
4. Mission Control mentioned the debris field started below their orbit and was working up. The second time around it would have been above them. Also, I'm not sure how it would have been flat.
However, the micro gravity interactions were fantastic and more realistic than I've ever seen. The debris punching through the shuttle, the ISS... was intense, and all the more frightening because there was no sound other than her breathing, and what you could hear muted through her suit when she was attached to the arm.
So it seemed they took great care and effort to recreate the details of weightlessness, and interaction of the debris with the spacecraft. Then for the macro movements they went Star Wars.
Still, it was incredible and enjoyable. I saw it in Real D. I really want to go back and see it in IMAX.