I like a modified hourglass shape the best. I like the front a smaller "bulge" than the back because the front of their little bum is smaller then the back. Reduces things to mess with when trying to diaper those pudgy little thighs and butt.
I don't use them other than nighttime and when I know she'll be sleeping for a longer stretch(like after a bath since they seem to really upset her). I just can't be bothered and wetness doesn't really seem to irritate her or her skin all the time. I like mine to go the full length of the diaper as well. Again, it just seems to work better to keep the entire diaper area dry AND going the full length of the diaper leaves less to mess with and make perfect when those pudgy thighs are bicycling rapidly and the mouth is screaming and the arms are waving and you are envisioning a geyser of pee arching towards you any moment.