yes. at 1080p you only need 2x AA to get rid of all jagged edges, because pixel density should be higher, and that makes jagged edges harder to see. And your 5850 can handle that easily.
It's not the screen size that helps make the jagged edges less noticeable, it's DPI. That's related to size and resolution. I find myself with a 1920x1200 resolution 24" monitor, and 2x AA does not get rid of all the jagged edges. Nothing actually does, but it does make it less noticeable, but I normally use as high as I can, as even x16 isn't enough to remove them. It just makes them less noticeable.