The preferred rooms at POP usually are facing the pool areas. Some may be a bit closer to the main bldg. I have yet to have a preferred room at POP....I get a regular, standard room and have been very happy.
Now, although you book a preferred room, you really can't request a specific room. You can make some room area requests, such as....60's, higher floor, or 50's, ground level.
If you get too specific, you may not even come close to anything you may like....for instance, don't ask for 60's, room 6410...the room assigner won't know what it is you are looking for, other than that specific room and if that room isn't available (good chance of that happening) they won't know what other room may fit your wishes.