I've been comparing 8 different headsets. The Jabra BT500 and the Plantronics Voyager 510 are both at the top. (I also liked the Samsung WEP200 but it's a different style so I won't compare it here) I work in a noisy construction environment and drive a noisy construction van so background noise is a huge issue. Plus I need the headset to stay put even when I'm lying on the ground, sideways, etc. This over and behind the ear style works well for me. I tested all 8 headsets by pairing two at a time and putting one in each ear, then switching between them while on the same call. This let me and the caller compare the sound quality equally from both sides of the call. In a nutshell, the Jabra BT500 wins on function and the Plantronics 510 wins on sound quality. Given that background noise is such a big issue for me, I have to go with the 510. The BT500 has better designed buttons that both feel and work better. But, the sound problems are: 1) The BT500 always sounds slightly more muffled, even in a quiet environment 2) The BT500 has the mic so close to your face that it often touches and makes noise, especially when trying to use a button and 3) in a noisy environment the Plantronics 510 wins hands down. With the kind of background noise I get, I couldn't use the Jabra BT500. I have to go with the Plantronics Voyager 510 and all the other issues have to take a back seat to the sound. For those that would use this in a quiet environment I can say that the sound quality is only slightly worse than the 510 and may not outweigh the better function of the BT500.