My vote is for Daytona. We made a day trip to Coco last year at the end of April and spent a week in Daytona this June. Coco seemed like it was just the beach and some surf shops. Daytona seemed like the area had much more to do. We went down to the lighthouse south of town, there is a Marine Science Center there too that was kind of cool. The beach was great. You could even drive your car right out onto the beach. If you are into cars, they have a bunch of stuff to do at the race track. Plus, they have all of the stores/restaurants that you could ever need on vacation. We had a lot of fun there.
Almost forgot...when we went to Coco the last week in April last year, I was suprised the water wasn't frozen. It felt like ice water. Plus, I don't know if there was a storm off shore or not, but the waves were massive. I wouldn't have gone swimming in those conditions even if it was warm. We went in to our knees, but that was enough.