A replacement for my old Sony Ericsson Bluetooth which was starting to come apart, and some online reviews suggested I try this to go with my Sony Xperia. The device is nicely constructed with a good feel to it and even though it looks bulky it is comfortable to wear, and Plantronics will tell you there is a waterproof coating on it so it will survive being used in the rain. Sound quality is excellent and it does have some good noise-reduction facilities as clearly noted by others with clear reduction in car and road noise when I am driving. Frankly I prefer having this on rather than holding the phone to my ear.
The controls are easy and quite solid to feel, including a mute button. Charge time is reasonable and it is fairly self-evident that the charge needs to be kept topped up or it will die mid-conversation.
Setting up, pairing etc. are very easy as per the instructions and it will connect to multiple devices. This is a 'smart' Bluetooth headset so it will tell you who is calling (up to a limit!) and give you the option to verbally answer or reject the call, which is fantastic (and thus truly hands-free in that context)! What it hasn't got yet is voice dialling and that is something to aim for. The old Sony Ericsson phones could be programmed to voice dial and worked very well; current Android apps in this regard are fairly hopeless!
And finally, a very stable device that sits on your ear and does not threaten to fall off with the smallest movement! Plantronics Voyager Legend Bluetooth Mono Headset - Black