Watercolor is a much larger property than Watersound but does have a variety of accomodations on the south side of 30a from 1 - 4 BR Condos to houses. Some directly on the beach many with some views of the beach. Watersound definitely is more laid back - more for those who want to just kick back, walk the beach or read a book. Nothing to do nearby except what's on property, so driving is required for other activities, including dining opportunities. Watercolor on the other hand has Seaside and Grayton Beach within easy biking distance with activities (movies and concerts in summer), spas and dining out opportunities ( pizza and family style eateries on property or close by ). My choice especially if you have kids that need entertainment.
I dont own rental property at either resort but I do work at Watercolor by way of full disclosure.