My daughter was 7lb 13oz. My son was 9lb 4oz. I can't really compare the two births well though, because my daughter was a lot of excrutiating 'trying not to push' as we rushed to make the hospital in time (crowning as we came through the ER doors), and with my son it was a relaxed home birth in a nice comfy pool. Just too many factors to compare the two.
my son did have shoulders like a line backer though... that was painful (but not a guaranteed issue with a heavy baby, and not a guaranteed non-issue just because they're light). My poor hubby didn't enjoy having to pull to get him free. lol.