We have never used a caravan on our three trips to Alaska, but have observed them in the campgrounds. The main draw it appears, beside having everything planned for you, is the social aspect. Many times we saw groups from the caravans congregated by an RV with afternoon cocktails. As we are not drinkers, this is not attractive to us. We also travel in a Class B and noticed that most of the campers with the caravans are large Class A's. There is nothing wrong with this, but it just seems that this is not our "style".
We have on all of our trips changed our itinerary for one reason or another. On was mechanical trouble that stopped us for 6 days, and the others were our choice either to stay in a location longer or leave earlier. All of these would have not worked with a caravan.
I did take the itinerary of a caravan to help determine some of the most popular places to visit on our first trip and on our next two trips we returned to the places we liked the best and added some places we had not visited before.
My husband and I do a lot of photography and will often just head off to look for things to photograph and we do not work on a time table. Thus a caravan is not for us, but might work very well for you. No one can make that decision for you.