I can attest to how great Bon Voyage's liquor option is. Last month I sailed on the Imagination and decided to do this. Called them up and ordered a bottle of Absolut Citron for $40 +tax. I think I was on the phone for maybe 5 minutes. They just ask for your booking number and verify the information and then you say what you want. There were 4 of us sailing together on this cruise so we were able to bring on 4 12pks of soda to mix with. When we got on the ship there was a note in my cabin from Bon Voyage instructing me to contact room service. Quick phone call to say I was in the cabin and about 5 minutes later there was a knock on the door. Bottle came with a nice ribbon and bow which I felt was a nice touch. While I had ordered it for myself, if I had done it as a gift for someone, the bow would have been great. We also went ahead and got the soda sticker, just because if I'm thirsty, it's not always worth it to hike back to the cabin. Carnival (at least on Imagination) uses the clear 16oz glasses when you order a soda, so all we did was make sure that every so often some of these glasses made it back to the cabin. Rinsed out and placed on the desk. The cabin steward never bothered them, and always made sure our ice bucket was full. Might help that after we rinsed them, they were placed upside down on a wash cloth so as to not leave any rings on the desk.
All in all I found the experience to be great. Yes I still bought the occasional drink at the bars when I was with the group and didn't want to go back to the cabin, but all in all compared to taking the same cruise last year, my bar expenses were between 150-200 less this time around.
Disney Dream - Dec 2012 4n Bahamas
Carnival Imagination - Dec 2011 4n Western
Carnival Imagination - Nov 2010 4n Western
Costa Atlantica - Dec 2009 7n Eastern
My opinions are mine and mine alone. They do not represent the opinions of The Walt Disney Company nor any of its subsidiaries.