This game is so badly programmed it was a waste of money for me. My PC is not a modern gaming beast but still shoul be powerful enough to play this game with a reasonable level of performance.
It's a Quad Core 2.6Ghz Phenom II machine with 4 GB DDR2 1066 and a Radeon HD 6970 2GB. Yet it dawdles on relatively low resolutions (even 1440x900 is too high) and is glitchy as hell despite using the lowest graphics settings. It doesn't look that good either. It's a resource hog. It reminds me of how games used to be on Windows 98. This game simply does not live upto modern standards of quality. It should not even be in the steam store, it should not have been released.
I don't believe this is particularly any problem with my PC because other games run fine (yes I am running latest drivers). Borderlands 2 will happily run at very high resolutions, max settings, at 2560x1600 smoothly for prolonged periods without crashing. Sins is stable for prolonged periods even when constantly maxing out the CPU in huge games.
TLDR; this game is crap, they screwed up trying too hard to make it look good or something. I want my money back, it isn't playable.