We did 16 states an 6000 miles last winter, from New England down the east coast to central Florida, then out the panhandle and around the gulf coast to Galveston. Our 2 favorite places were HoHum in Carabelle FL and 30A. We had never considered moving out of Cape Cod, but if we did, we'd go to the Santa Rosa Beach area.
It's not bad during Spring Break...you don't get the college kids too much in that area. They normally stay more over near panama city beach, where it can get more rowdy. Spring Break in the Santa Rosa area is more families than anything. And with schools having different spring break weeks, you don't get a bunch at once. I know when we've been down there before and our daughter was out for spring break, that their schools were in session.