I would think about what is important to you for room location and requests. As mickeynut1 mentioned the resort is fairly compact. However, the monorail, bus stop and boat dock are all located in different areas so it will be impossible to be near all transportation.
Will you be using the pool a lot ? Do you want a certain view, no connecting door, corner room etc. Think about what you actually want in a room and then request that. I often suggest to just request what you want, "near monorail" etc. It gives the room assignor something to go on other than just a building.
As mickeynut1 mentioned Big Pine Key is often requested for proximity to the main building and pool but you will be farther from the bus stop and QS location. So, back to my think about what you want and what services you will use most often.