I bought a set (left & right ears) of Ovation Boost. My right aid was a great improvement-the left, not so much. I had sent my audiogram to the company for custom programing, but the left aid wasn't helping. (my left ear is worse than the right. I called the company and the emailed me a return form. They re-programed the left aid in 2 days and sent it back. Now the left aid is as satisfactory as the right. I think that the customer service was impressive. The aid spent more time in the mail than the repair at their shop. Even though this site is for "pissed-off" customers-sometimes an "atta-boy" is refreshing.