49 FPS on high, 31 FPS on Ultra on 1050p. So that's not really terrible. What I would do is turn off anti aliasing but keep 1200 resolution. Anti Aliasing is in a sense forcing a higher resolution, while having a higher resolution monitor is naturally giving you better resolution. I prefer to have higher resolution but less AA, but that's me. You'll have to tweak your settings a lot though, but with the 660 it at least looks like you're going to be in the high quality range.
Something I didn't bring up earlier, is you also need to have a fairly decent CPU to pull off good frames, if your CPU is just as good as the 660, you should be fine, if it's lacking you might end up seeing worse FPS.