Any of those three would be nice....................
WL - beautiful hotel, smaller in size so I felt it more intimate, nice pool area and great proximity to MK. We loved it there.
AKL - beautiful hotel, much larger but then they provide many activities for the kids and even some entertainment. Of course, you have the animals. Great bus service so location is not an issue. If you have the ability to do concierge here, I hear it is a treat. I would go here while your child is young, mine at 9 & 13 loved the experience. This trip at 11 & 15 were bored. So while we love it there it is time to move on....
BC - have not stayed here but have visited a few times and have family who stayed. SAB is awesome, and if your son loves the pool area you can't go wrong. Walk to EPCOT or boardwalk which gives you lots of dining options. Boat to MGM. Good central location.
AS - have stayed and would never go back unless it was greatly discounted and I had no plans at all to be there except to sleep (if you can sleep). Pools are nothing and food court was like a school cafeteria. All our meals had to be offsite, which I found very inconvenient. AND you may get stuck with school groups. We went there in May and it was overrun with cheerleaders for a competition. They cheered outside into the wee hours, hard to sleep.
I think your son will have such an awesome time at one of the other hotels that it won't matter in the end. While he may not have the silly decor, he will have great pools, activities, good eats, and happy parents
