Thanks everyone for all of the input, after much consideration I have decided to do the b2b on the explorer. Except for Mykonos, the b2b goes to different ports each week. Venice is one of my favorite cities and this year at least, RCL has a transport from Venice airport and city center. Price wasn't a factor, but the b2b was over $1000 cheaper. I will do theOdyssey some day.
judy