I haven't been to Fantasia Gardens, but we went to Winter/Summerland. We had such a great time. We did the Winter theme. It was the beginning of December and the theming was great. The kids had a ball.
I've been to both Fantasia Gardens and Winter/Summerland, and they're both very cool. Fantasia Gardens, IMO, is a much harder course than W/S, so if you have younger kids with you that might be something to consider, but both are fun!
We had lots of fun at Fantasia Gardens. Sure, there were a few harder holes, but my 6 yo dd got a hole-in-one on the cave hole. That was her first and created a great memory!
Yes, there are some water surprises on the course! There are two courses there, and one didn't have the Fantasia gimmicks - just nicely groomed, hilly holes. With kids, of course, we went for the dancing hippos!
We loved Fantasia Gardens golf. Only problem I would say is the lack of shade as you go round the course. My son was only 7 when we done this and had never played golf before so took ages to do each hole. The result was we were all cooking by the time we finished!