Shelly makes a good point that at OKW there are numerous stops, but those stops are a short distance from your room. At AoA, its a hike back to the Little Mermaid rooms (did it last month, not bad, but I didnt have cranky kids with me). OKW also has the boat service to DTD, which I really like, very tranquil. AoA is busses to all resorts. AoA is pretty far from all the resorts (right at the southeast entrance to the property) and OKW is probably closer to each resort but AK. Both have great rooms. The theme at AoA is out of this world. They did a great job in my opinion. OKW has its own theme which I like.
OKW;
Pro: Large Rooms
Key West Theme
Boat to DTD
Con: Far from AK
Older resort
AoA
Pro: Large "suites" (in all but Little Mermaid)
New Resort
Beautiful design theme (imo)
Con: Long walk to some rooms from bus stop
One of the longer bus rides on property from resorts