I edit 720
a) Because I export to 720
b) because my system seems to deal with it better (I know that makes no sense as its having to rescale as well as everything else, but there you go)
c) because I can pan and scan the 1080 footage
I know That I could edit in 720 and upscale the footage to pan and scan knowing it would downscale it again when I export to 720, but I just balk at doing that