I think, like so many things, the answer is "it depends." It depend on how you travel, and who is in your group, and what kind of traveling you've done before.
We did an
ABD to another country, Peru, as well as one here in the US, Southwest Splendors. The cost of the trips for our family of 3 was only a few hundred dollars different.
We thought that the Peru trip was so much more "worth it." And for many of the reasons already stated: the hassle factor was nil, we didn't have to worry about the language differences or safety, and we covered way more ground than we would have otherwise. We felt that we got great value for our money.
We had a great time on the SWS trip, but also kept looking for anything that made it "more" than we could have done on our own.
Having said that, either trip was worth it in terms of educating us on a better way to travel. Since these trips, when we have gone to new cities, we have engaged a guide for a day. We've learned to look for the "sneak routes" to avoid lines and to get tickets in advance. We have booked nicer hotels because we discovered that it makes a huge difference to our overall trip enjoyment.
And that's where the "depends" comes in. If you hate to research, and don't want to spend the time to craft an ABD-esque trip on your own, then it's worth it, even here. But if you are the kind of person who can pretty easily figure out what goes into the US trips, or who can look at an itenerary online and figure out a way to copy it, maype not so much. If you've never done much "luxury" travel, like we hadn't up to the Peru trip, it's worth it just to set a standard, imo. Or to find out if you even care about that kind of stuff.
Finally, one other thought: if you have anyone in your travel party who is high maintenance - for whatever reason - you might be better off letting Disney worry about things like food and potty breaks and constant entertainment.
Whew - very rambling, and not sure I helped. The short answer to your original question, in my own experience, is Yes.