From a sound quality stand point the M3000 and its noise cancellation is the best I have tried so far. In a real life test in my Rx330 the other party could not tell I was in my car talking. With all of the other headsets they could. Size and comfort were my isues. It is large and a bit geeky looking. I think I would have put up with that if it just didn't hurt my ear so much. The earpiece is hard plastic and the earhook sort of presses it against your ear. The combination hurts after a while. It may be different for you so I can't say that it will hurt everyone. The Tekkeon had the best sound in a quiet room but couldn't compare in a noisy envrionment. I have not treied the SE660 or HBH 300. Many people swear by the lattter with the biggest complaint being either too low a volume or hurting or requiring an ear gel to get the volume to a reasonable level.