Candid assessments of ACA tours can be found on Bike Forums. You'll find that there's lots of whining, probably something that ACA would prefer not to sponsor here. CGOAB has journals organized by ACA route.
I probably don't have your skills in the dark arts of internet search engines but I couldn't find a forum dedicated to the ACA guided tours, or even one that references them.
What I was thinking of was a forum that someone could see conversations about all the Guided Tours in one place. This way, someone who is wondering if they should spend a grand on a guided tour can get more info from the reviews, questions and general chatter that should evolve there. Also, if all the threads re guided tours were in one forum, it would help the choosing of one over the other.
If some opinion is negative, that will help ACA correct the problem, if any. If it is unwarranted whining, it would be obvious. I don't think ACA should have a problem sponsoring open discussion of their guided tours.