Well, it may be a Ford vs Chevy sort of thing. However, I'll offer a few thoughts about why I like Coach Net better.
All AAA policies are issued by state AAA organizations and may or may not always be honored in other states (but mostly they are). In some cases you may have to pay for the road service and get reimbursed later. And if the dispatcher you reach is in a state that doesn't have RVPlus policies, there could be some delay or confusion.
Coach-Net, on the other hand, is national and dedicated to RVs - that's what they do. And they are accustomed to dealing with big rigs, so know what sort of help you may need and how/where to get it. They also have an RV tech support staff on hand to help answer questions and fix problems, even if the problem is just that the furnace won't light. And one policy covers your RV and all your personal cars, for one flat price.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL