Further down the hall and higher up will tend to have better fireworks views - but some of these rooms are blocked by trees and most of Illuminations happens low to the lake. These are the least convienent rooms in terms of access - if you want easy getting around, you want a low floor (less stairs) and or close to the elevator.
My standard warning, in all my BWV stays I've never had a location request met. If I ask for high floor, I find out how lovely it is to be able to walk out my room to the pool. If I ask for close to the elevators - I find out how nice it is to be near the end of the resort closer to MGM.