We are trying to decide about the Pompeii/Sorrento/Capri tour as well. Pompeii is the requirement for us and I've wanted to see Capri for years. DH is intrigued by the 4x4 trip to Vesuvius and Pompeii and Wine tasting. After much reading about the summer traffic, I'm a little worried about non Disney options.
It seems like there is a great deal of availability if you try to book our cruise. Maybe we just have a bunch of very hyper planners?
There was an article on MSNBC yesterday on this exact trip. We have booked it, thought it looked like a fun time. Here is the link to the story;
http://today.msnbc.msn.com/id/42456357/ns/today-todaytravel/
In case it doesn't work the title was, "Touring the ancient devastation of Pompeii" and it was in the family section of the travel section of yesterday's MSNBC site.