Cindivan - We are taking our first RSSC cruise next week. I too have always planned independent shore excursions and share your same concern. We booked this trip in May and were considering 3 different cruise lines - RSSC, Azamara and Oceania. In the end, the RSSC was the best value and we have friends that are loyal RSSC cruisers that have been trying to get us on Regent for years.
The quality of the shore excursions will have an impact on how we evaluate taking another Regent cruise. We have cruised on Oceania before and really enjoyed it.
I'll let you know what I think when we return home in September. To be honest, I have missed researching independent shore excursions that do exactly what we want to do in small groups of 6 - 12 people.