Shelleebell, I didn't realize from your post that you were *specifically* asking about Italy trips, since your husband is Italian. I saw that in your reply to another thread. So I'll try & answer from the "just Italy" point of view. I haven't been on any of the regular ABD Italy trips, but I did the ABD add-on to the Disney Magic's Med cruise, and a lot of the activities overlap.
As far as Italy is concerned, both Italy itineraries trips have their advantages. Do you want to go to Rome? Only Viva Italia (regular or Signature) goes to Rome. Bella Italia does not. Bella Italia includes Florence and Michelangelo's David, which I adored. It also includes the Amalfi Coast and Pompeii. Viva Italia goes to Venice, which lots of people love, and spends some relaxing time in Tuscany. Really, both trips are wonderful, and you just need to look at which activities sound more appealing to you.
As far as the "regular Viva Italia trip vs the "Signature" Viva Italia trip, if you check out this link, it gives a point-by-point comparison of the 2 trips.
http://abd.disney.go.com/abd/en_US/general?name=ItalyGatewayComparisonPage
The main differences seem to be: the hotels are upgraded, it includes 2 more dinners (but 2 less lunches), and it includes the 'Secret Passages tour' at Palazzo Vechhio. There are a few other upgraded "touches" apparently, also. If that is worth the extra money for you, go for it. But most people I've heard who've gone on the "regular" Viva Italia trip rave about it. And I've heard lots of compliments on the hotels, and no complaints. I think you'd do wonderfully with either. It's just whether you're looking for the "luxury" version or not.
As I mentioned in my reply on the other thread, check out the Trip Report sticky at the top of the ABD forum. There are a few Trip Reports there from folks who have already been on these trips.
Sayhello