This is the third pair I have purchased. I received the first pair as a present after it was recommended to my wife. The feel, sound, controls are all great, but after three months the unit would not turn on. It was still under the 12 month warranty and Plantronics replaced them with a new pair. The second pair lasted me about a year before the left speaker quit working. I was now outside the 12 months, which brings me to my third pair. I use these 3-4 times a year at the gym where I can work up quite a sweat. While these are "sweat resistant", I question what that really means. I believe it is the sweat that has shortened the life on my second pair. Would definitely give these 5 stars if they would either extend the warranty or develop them with greater moisture control.