I have bought and used many Bluetooth headsets. The HS850 is, by far, the most user friendly and consistently reliable to date. I operate heavy mining equipment for a living, and even while driving a concrete mixer down the freeway or running a 90 ton earth mover at the mine site, this device allows me to safely and comfortably engage in a phone call. If I get a call, I pull it out of my front pocket, open the boom, put it on my ear and start talkin'( or if I'm already wearing it, just press the button ). Hanging up is simply the reverse.If you prefer the sound and fit of ear bud style speakers, this device may not be what you want. However, even in loud environments, the speaker of this device is more than adequate to hear the caller.The noise canceling feature of this device works better than most I've tried. I can stand near an idling Cat C-13 (a very large diesel engine) and still be heard clearly, and with little background noise...according to people I talk to.The only reason that I rated it 3 stars and not 5 is the disgusting, pathetic, weak, fragile, no-excuse for, ridiculous, lousy, clumsy, someone should be fired for this, charger plug. I'm on my 4th unit because, after about 6 months of daily use, the plug will slowly quit making contact with the headset. I suspect that the tiny little hooks that hold the plug in wears out the plastic housing of the headset. Buying a new charger only gets a couple more weeks out of a headset before the same thing happens.All-in-all, this is a great headset. But, if you use it every day (as I do), expect to replace it within a year.