I've done it and ridden quite extensively. There are some decent climbs on it. With GT rides, you either have to stay with the group or read the map/cue sheet. The group maintains a social pace--maybe 13-14 mph. In general, the GT rides in Bartholomew County are very nice. Randy and Connie do a great job.
Just remember that in a group setting like that, you need to use either voice or hand signals to warn of any cautions, turns and the like. Voice signals work well for a lot of things, but IMO not as well with things like potholes. I know you've expressed some issues with taking one or both of your hands off the bars. If you go, I would suggest staying at the back.