Audio Branding - feedback request

Good morning, we are interested in hearing any feedback on Audio Branding firms you have worked with. Our goal is to improve our on-hold experience, use custom music as a marketing tool and so on. We are new to this approach and so far have met with PHMG who seem to be the biggest vendor in the market space. Who else have you worked with? What results have you had? Any war stories or warnings? Any and all feedback is welcome. Looking to have this in place in the very near future. Thanks to all. Barb