Personally I prefer Stow on the Wold to Bourton on the Water. I have visited the later one 14 years ago while doing an exchange program in Oxford.
Stow on the wold is so much quieter and less commercialize comparing to the Bourton on the Water. We visited both towns in the same afternoon only to find ourselves being surrounded with day trip tourists from London in Bourton on the Water.
Spring afternoon in the Cotswolds is beautiful. We caught the best sunset while we were exploring St. Edward Church. The door at the back of the church reminded me movies like Lord of the Rings.