Hi,
I actually just got back from doing a split stay between both resorts.
The pool at AKV-Kidani was really nice. If you have really young kids, the entrance to the pool is zero entry, so they can just play in that area. There is also a small slide that they can go down with you waiting at the bottom. Then there is the water area. My boys who are 5 and 6 loved it. When I was there, the pool area was fairly quiet and it was easy to keep an eye on the kids.
The pool at BCV was crazy. There were so many people and kids running all over the place. We mainly stayed in the sandy bottom area. It was kind of hard to walk on it, but the kids did love playing in the sand. It was a little harder keeping track of 2 kids because of all the other kids running around. I liked it, but I think I preferred the pool at AKV.
If you have any other questions, please feel free to ask.