We did the Alaska caravan run by SMART in 2013. Never again! Poorly run, disorganized and led by a lazy wagon master and an incompetent tail gunner. Just to add to the entertainment :R about two weeks into the trip the wagon master and tail gunner started a feud with each other and spent the rest of the trip not speaking. Most of the participants were medically fragile and the staff refused to give them the support they needed.
Some of the people we met were very nice, others not so much. Several have since died, so they were able to check off a bucket list item before they checked out.
My observation was that if you join a caravan, you'll meet lots of people that have all the independence of a flock of baby ducks. :B