I have been to the pools at Beach Club, Boardwalk, Saratoga Springs and Kidani. Here are my thoughts:
1) I thought the Beach Club pool was beautiful. I didn't like that the kids had to walk so far away to get to the entrance to the slide. It requires them to leave the pool area and cross the bike path, which is highly traveled by non guests. I also didn't like that there were so many nooks where I couldn't see the kids. I didn't stay there long, but from what I saw, it seemed like a very nice place to be if the above things don't bother you.
2) The Boardwalk pool was the least landscaped and least impressive from a "looks" perspective, but the entertainment there seemed more lively during our summer trip. It seemed like people were the most involved there.
3) Saratoga's main pool is very beautiful. We really enjoyed it. We also liked the other smaller pool that had a nice theme to it. I can't remember what section it was in exactly, but it was on our way to our Grandstand building. In fact, the pool might have been in the Grandstand section. For those who know the resort better, it is the one where the kids can squirt each other.
4) We just got back from Kidani. Once again, a very nice pool. I think we would have liked it more had the weather been nicer.