I tried two other headsets and found them uncomfortable and without the clarity of the 510. Whether in my car or outside, those with whom I speak always comment on the clarity of the call. Linking is seamless with my Motorola E815. I often forget my phone in the car, walk into a WAWA and the headset beeps telling me when I exceeded range (about 15 feet) yet when I return it picks up the connection again and off I go. The battery life is fantastic as I went an entire week and a half on one charge.I could not be happier with this purchase and Amazon had the best price by $30.Wishing you all the best in your next purchase.