Our kids last day of school was June 4th (which is REALLY late for us but we had a lot of snow days). They start back to school August 21st. Typically they are done somewhere around the 20th of May so they get almost 3 full months off.
As for the kids - they of course prefer summer break! Swimming, playing with friends, sleeping in, camp, etc.
As for me - GIVE ME SCHOOL! My kids do much better when they are busy with school and when they are in a routine. Plus the house stays clean during the day.
I do like just having to get myself up in the mornings though. I think summer break works out just about right. At first I'm all excited because I get to sleep later too and there's no morning rush. About the time the kids start driving me crazy at home, it's time to head back.