I noticed there is an optional system update (3.73) lastnight. I checked the notes online and it said it was to fix some "stability issues". I downloaded it and played for 2 hours at level 30 with little glitching and no freeze ups. It could be coincidence because this playthrough I'm trying to limit myself to no companions, I sell all but a katana and a sniper rifle and my save file size is half f what it was at the same level last playthrough.

You have to go into the system update and trigger it in the xmb. to try it.