So the following is my "UNOFFICIAL" suggestion.
We stayed at SWAN - which I would recommend over Dolphin because it has Queen beds.
Some may say Dolphin as it has more "stuff" but we would just walk over there. Every evening - I would take a nice walk over to the convenience store on the first floor of the Dolphin. I actually just enjoyed the "me" time of the walk.
However suggestions for rooms
1 - LOVED having a balcony - so if you can - suggest getting a balcony
2 - I Recommend for SWAN the following. As you are LOOKING at the SWAN FROM the DOLPHIN - there are two arms of rooms. I suggest a room on the RIGHT ARM or along the back. So that you can see the DOLPHIN and all the action coming in and out of the lake. Otherwise if you want to further upgrade - an epcot view. However for us a balcony was more important.
3 - I would avoid any room that overlooks the convention space or another roof - they are loud (roof top air conditioners)
4 - I also suggest getting the appropriate CC that is aligned with the resort. We basically got a card and paid for the room exclusively with points
I have highlighted the rooms I would go for in RED. Obviously higher floors give better views