We have USAA for Home and Cars, so we added Boat and RV. A few years ago, USAA recommended shifting Boat over to Progressive, saying Progressive had better boat coverages and USAA was an Agent for Progressive. Price came down and coverage better. Then USAA recommended Progressive for RV. Once again, better coverage and lower price. The customer service number at Progressive answers "Progressive for USAA Members" and I like that. So, saving a little money on coverage that's better matched to Boat than a "Floating Car" and RV than a "Really Big Car."
So, with Good Sam connected to Progressive (the only one on Keith's list I've had any dealings with), my take is that might be a good start.
If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB