My husband and I did Viva Italia in June 2008, and it was great! Disney does a first class experience, no matter which tour. We booked an pre-tour day and a post-tour day which gave an extra day in Rome by ourselves and a final day in Venice after the tour.
It is an all inclusive tour (tips are included) except for flights and souvenirs. Only meals apart from tour days are your responsibility. Again, it is absolutely worth it. Can't say what our favorite part was, and we had no complaints.
Disney handles all your luggage from point to point (place your bags outside your room at night prior to leaving and see them again in your room at your next destination!)
No queues for any of the sightseeing stops, this is all arranged. You have a reserved time.