We've stayed at both Gulf Waters and Indian Creek several times and we prefer Gulf Waters. IMO, Gulf Waters is quite a bit nicer: newer, Gulf Waters is mhs only, Indian Creek is mostly mobile homes now, Gulf Waters seems to be a younger crowd but Indian Creek is still nice, can be much cheaper, is bigger so has more amenities (3 pools I think) and has more activities. The last few times we've tried to stay at Indian Creek, I don't think they had any spots available.
I don't think you can go wrong with either. If you do want to go to the beach, it's a few miles away (not like Red Coconut which is on the beach or across the road) but from either you can take a short trolley ride (when it's working - not the most reliable thing in the world) (we've also biked to the beach from GW) and we'd rather stay at either than at Red Coconut (we don't spend that much time at the beach and we'd rather have access to pool and hottub and we like having more space and doing other activities like walking or biking around the park with the kids and that's better at GW or IC)