I've noticed anything above medium shaders really makes this game chug. I can't really tell the difference between medium and high except that the contrast turns up a bit. Meh, oh well back to medium.
As for the rest of my settings, I leave everything else on high except post-processing(thats also at medium) at 1920x1200. Its very playable, and still looks very good(imo) so I'm happy with my performance so far.