We absolutely loved SAB - but my dd was 9 at the time and a very strong swimmer. There is a lovely zero entry sandy area (the sand bottom and beachy transition is one of the coolest things!) and over in the "shipwreck" (where the waterslide tower is), there is a smaller children's pool with a modest slide for younger kids. However, I personally would not love it for a younger child. Even thought there are lots of very nice, vigilant lifeguards, I still would be always anxious to have to keep track of more than one child. The pool is very deep in many places and the lazy river has quite a current. It would be easy to lose track of a child. For that reason, we will do AKL or other less aggressive pools until our kids are older. AKL - Kidani has a water play area in addition to a pool and then you can also use Jambo house's feature pool. People who have stayed at the Poly (I'm sorry to say I have not had that pleasure) absolutely rave about it. Similarly, people love the theming at WL. Just today, someone was commenting on how much they like BWI's pool and it is a more enclosed area - easier to keep track of the kids.
When I clicked reply I thought I had photos, but I did not upload the ones I wanted to photobucket. I second the pp suggestion to checkout allears.net. For AKL be sure to check out Animal Kingdom Lodge under delues resorts and then also AKV-Kidani under Deluxe villa resorts to see those pools.