I'm not sure about fewer kids, but when we ate there it was certainly much quieter and laid back than the typical buffet "character cattle call." AKL is worth a trip just to check out the lodge, the animals, and the wonderful cast members from Africa. AKL is really one of the gems of WDW - beautiful, relaxing . . you really feel like you're on vacation.
AKL is on the "hinterlands" of WDW property, but we always had good luck with bus service. If you're going to go to AK for the day, you could take a bus from your home resort to AK, and then take the bus from AK to AKL for breakfast.