dunno what are you talking about... on stock GB I never had any issues with 1080p recording... its its definitely to do with the rom or AOKP in general. Too many bugs for me here... Im tired. will go to roms based on samsung for now. so much better and smoother experience. Would like @westcrip to make one for AOSP also. He is one of the best devs and issues come mainly from AOKP. Which I find being in early betas as to this date
Try pointing your camera at the same subject, from the same distance, then change from 720p to 1080p. Then you will see what we are talking about. The camera is more zoomed in when in 1080p mode.