I have been on 5 Caravans as a customer. Everything that Russ and Tequila said is correct in my book. I saw things in Mexico that I never knew existed. I went with Adventure Caravans and would recommend them.
There is one misconception that many people have and that is you travel in a huge group all the time. This is not so. In the caravans I went on RVs were sent off in waves about 30 minutes apart with 3 or 4 rigs in a wave. We were given times to be at a specific location or RV park.