I did hesitate a lot myself too between a Tower 1 D unit and Tower 1 B unit, finally settling for a 'B' unit.
You may want to consider the following topics when deciding:
- the smallest of the bedroom in Unit D has a very close neighbor, making privacy difficult unless you close curtains all day
- the 2nd smallest bedroon of unit D also has some (more distant) neighbours directly visible from towers 8-6) - again, you will have to close curtains all day
- the living room of the D unit is smaller than the B, and some valuable space is eaten up by the balcony.
- all bedrooms and living room in the B units have aboslute privacy; from there you can only see seaview and Ma Wan and the bridge
- the living room in the B unit is squarer and larger, making it look much bigger than the D unit, and making it more convenient to decorate and plan
- the master bedroom of the D unit has a dead angle to your left when entering - you can only build a wardrobe in there and this will eat up a 1/4 of the room area
- finally and most importantly, the D units face West, making them hotter in summer; you will also have less wind coming in thru the windows
The B unit, on the other hand, faces South and enjoys most breeze (HK has mostly southern breezes in summer).
After lengthy considerations, I settle for a high floor B unit - am still amazed at the views, and the nice breeze coming in from the south.
Enjoy Bellagio!