Did some playtesting wbitd but never a campaign game. Cat and Mouse was the closest we came to playtesting one. Played a ton of RB CGs. Fish thought the CGs were the greatest thing ever since there was finally a tomorrow.
The work that goes into developing a CG has to be time consuming. Seems like quite a commitment and I applaud you and your playtesters for doing it. Again good luck and good gunnin to you and your group!