They do both use the main depot. I'm pretty sure 14 is non-smoking. I know 15 is. We stayed in 15 and loved the easy access to the bus depot, food court, and main swimming pool. 14 is a bit closer to the food court and swimming pool, but a bit farther from the bus depot (although only a few minutes).
What about 16? I think that is the one we are going to ask for. I know we will probably wind up with a view of the parking lot but we will have three children with us and I think I would rather be closer to the car and everything else than have a view.