I have to call BS, on that Pez. I just had a 5770/5750 and could not play it on high. Even more I juts upgraded to two HIS 6870's and there are still times when there is a little lag. However, I do have a lot of settings on Ultra with the two 6870's. That being said there is no and I repeat no way one 5770 runs BF3 on high.
Okey let me re-check the system settings, and tell you back what.. even I will record on video to probe it if i'm right. and if not I will let you know you were right.