My favorite resort is WL... but in your situation I would go with AKL. We are DVC members at both resorts and it is not worth paying extra for a garden view room at WL. The garden view means you look at the trees. I can't believe it costs more to get that vs. AKL.
We just stayed at the AKL a few weeks ago - great trip. We had our neice staying with us and it was a ton of fun for her there. There are lots of activities for kids to do there, and even though you won't have a savannah view room, you will have plenty of opportunities to go out and sit on a balcony and just watch the animals - kids love it!
Pools are similar, architecture is similar (and yes designed by the same person), but for the experience, AKL would be more memorable.
My brother-in-law did the 5 person thing with his kids on the bunk bed room (2 adults, 3 small kids) and they didn't have a problem... they made a temporary sleep area for the youngest on the floor (also 2 at the time) and he didn't mind a bit. You could also do the head-toe sleeping arrangement with the 2 youngest (at those ages, their legs fit pretty easily in the middle with their heads on either end). It wouldn't really make much of a difference getting 2 queen beds a WL - you instead get 3 kids struggling over who is going to sleep in which part of the bed ("no, I'm not sleeping in the middle, you sleep in the middle. No, I don't want that side, you sleep on that side" etc.) Kids think bunk beds are much cooler than regular beds, too. If you are lucky, you might get upgraded to a savannah view! On 3 separate stays there we did... as did my bro-in-law with his bunk-bed room!