I dunno I run a pretty stout system and late into my latest game I am only getting about 25-30 fps according to FRAPS. Athlon X2 3Ghz, 4 GB RAM, 2 x 8800GTS 640MB in SLI should be able to run Sins all day at any resolution. Too bad the saves aren't compatable because I would like to know how the same exact battle would perform on 1.05.
And yes, guardian shields are graphically annoying.