Lee and I recently went on an organized birding tour with a well-known and respected company with a well-known and respected guide.  Practically EVERY bird was scoped, including warblers, vireos, wrens, and flycatchers.  HUGELY frustrating, as only one person in the party could look at the bird at a time, and the leader was so busy following the subject in the scope that he spent very little effort helping the rest of us get bins on so we could actually see the bird on our own.