I just did a b2b. It's very cool...for about an hour or two you feel like you own the ship!
Especially if you don't have to change cabins. The one I did, the only thing was that for a while you can't get into your cabin, so pack a bag and enjoy sitting by the pool and being the first one in the lunch line!
We are thinking Celebrity Soltice to Ruby Princess...out of Ft. Lauderdale...4-17-2011 > 4-24-2011...to... 4-24-2011 > 5-1-2011...The more I think the better it sounds... Any advice on changing ships...even though the same port?