I preferred AKL to WL, though I would happily stay at either again. I thought the bus rides at AKL were great, since the bus doesn't make any other stops it's a straight-shot to the parks, and the buses came very often. We never waited more than ten minutes. I actually think I got to the MK faster from AKL than I did from WL. Though the boat ride from WL was very, very nice, it wasn't what I would call fast and they didn't come as often as the AKL buses, then in the afternoon the boat goes to FW before the MK, making the trip even longer. I did not like the WL buses at all, having been spoiled by the AKL buses not making any stops. I didn't ride one single bus all week at WL that didn't stop somewhere else before going to the parks. AKL's pool is huge and has a zero-entry area. It has a lot of lush landscaping and nearby seating if you'd like to eat near the pool rather than inside Mara.
WL's courtyard area was prettier than the pool area at AKL, IMO, but the pool is smaller at WL. I preferred AKL's theming to WL's, but not by a lot.
I don't think you can go wrong with either choice, really.