On the PC especially racing sim I will take 1080p over 720p any day if it only cost me an average of 3 fps and still in the 50-60 fps range. (I choose Dx11 over DX9 in F1 2010 and it cost me 10 fps) Screen tearing is less noticeable when framerate is as high as 50 fps since your brain has no problem smooth out the image. I didn't see anyone complain about all the tearing until this article. If Gt5 was running an average of 30 fps the tearing would be a lot more noticeable.
1280X 1080p is still 1080p as the vertical lines are more important in a sim. That's because you are often looking down the track and more vertical lines means more information at the horizon. Of course if you don't have a 1080p montior/HDTV it's not going to help you.
