I currently have a Gtx 680 and have decent framerates but of course new maps are more taxing to run. It's gonna be a while until I can upgrade to a better card, so in the meantime are there any advanced graphic settings I can tweak to improve performance without the game looking blotchy?
Definitely turns off reflections as they're a big performance impact. Other than that, there isn't much you could do
Turning SSAO off helps a lot too, that with reflections are big performance eaters. I have always kept shadows at partial instead of full. Light quality and shader quality at normal are a lot easier than at full, but also visual quality suffers.