Initially, I had to return the first set as the call control button would not work. I contacted Plantronics by email, and after several attempts talked with a representative who determined the button indeed would not work, and I should return it. This was accomplish very easily with Amazon, and I now have a totally working Voyager 510.I do not use the headset extensively, but when I do, this set really meets my needs. My first headset was a Motorola that just set against my ear, and I had a hard time hearing with it even at full volume and especially with any outside noise. The Voyager not only has better volume capacity, but I believe that the earpiece being inside the ear really helps with the overall ability to hear. Those I have talked to also claim that I am clear and distinct. The headset is very easy to set up and adjust, and I use a RAZR V3.Finally, when the Voyager is in place for just a few minutes, I can barely tell that it is there. Ergonomically, it is great!