Slight improvement in Performance, but buggy.
If you tab out of fullscreen back to desktop and then back to fullscreen again, theres a big chance of bloom effects and weapons textures going all screwy.
Running a GTX 480 here. The performance is a tad better, but everytime I alt-tab to the desktop and head back, the screen is completely colored with a single color (usually blue or yellow) for one or two seconds. Nothing to worry about, just a bit annoying.
The game still stutters extremely bad on Starbase 1, I simply don't know why sometimes it is really difficult to move or look around there. I hope this gets fixed sometime in the near future.