When I called to get the rates that they offer for wedding music, it was explained to me like this- Bob Egan Entertainment screens the musicians that they send to you so that you don't have to do it yourself. They have hand-picked a group of djs, vocalists, musicians- whatever you need entertainment-wise for your wedding or special event- who are of the best quality. The prices were affordable, I hired both my DJ and acoustic guitarist from them. I was sort of 'assigned' to my DJ based on availability, but hired the guitarist based on samples of his music available on the Bob Egan website & they also mailed me a CD of his music from which to work from.
Pros: Easy to work with, very helpful and affordable prices
Cons: It's a little nerve wracking to be 'assigned' to a dj that you haven't chosen yourself, but it worked out well for me!