Greg,
Congratulations. A couple we met on the PG in 2005 got the very same type of upgrade and loved it.
We just found out we got upgraded ourselves for our cruise in the Med next week...H to D. No difference in size or appointments in the room. However, with Voyager's reported vibration problems in the aft cabins, the location of our new room means we shouldn't have to worry too much.
Congratulations again. Have a blast.
Jan