Hopskip -
We stayed there last November and didn't have any problems with the buses. I have heard, though, that you might want to use the first bus stop as buses didn't tend to stop at the other three if they were full when leaving the first bus stop at POR.
We stayed in bldg. 15. It was a nice location. Had two rooms and one was a corner room. It overlooked a courtyard area and was very nice. We liked the location. It was close to the bus stop, food court and main building. The main pool wasn't far away and the quiet pool was just a hop skip and a jump, as some would say.
Keep in mind that if you stay in the Alligator Bayou section that there are no elevators to the second floor. If you are using a stroller this can be a challenge, especially at night with sleepy kids. We requested a ground floor room.
Bldg. 14 is primarily reserved for handicapped guests and is often hard to get into. I have also heard some say that they don't like it because of the "foot traffic" around it with it being the closest building to the food court. Bldg. 18 was also in a nice location, especially if you have a river view room. The foot path to the main building, food court area is just right there.
Hope that helps.