Summary: Purchased to use for off-site web-based meetings for work. Used once and the audience complained of poor quality sound, horrible breaking up. When I tried to mute it - it would not allow me to unmute easily. Had to use alternative phone. Did not stay on my ears well/slipping. Have not used since. Have not tried to use it for just listening to music. My husband went to office supply store and bought competitive product for $65 which works perfectly.
Summary: A cheap headset that's comfortable to wear and works well as a mic (my friends no longer whinge at 'hissing' in the background of my skype calls). Speakers are perfectly adequate; not hugely bass-y but these were so cheap I don't feel I can complain about this. The headset also comes with in-line controls for volume and disabling the mic which I didn't realise, which is a plus. Cable is also nice and long (probably 1.5-2 meters).
Summary: I purchased this as a replacement for Plantronics 345 (http://www.amazon.co.uk/Plantronics-Behind-Enhanced-Multimedia-headset/dp/B000VDB0DW). Seconds after putton on the 646, I wanted to take them off and return them. Cons: - uncomfortable (hard plastic) - very small unadjustable headband (ok only for children, not even teens) - abysmal sound reproduction - I cannot stress how poor this is. It is VERY tinny. Unusable for listening to music.
Summary: I've used a few different headsets over the past 6 years but all have been conventional top of the head style. I decided to try a set of Behind the head style and I'm glad to say I am delighted. The Plantronics Audio 645 DSP are comfortable to wear and the audio has plenty of base (I like plenty of base when listening to my Music and Audio Books) the head set uses single cable with a USB2 plug on the end and the cable length is more than adequate.
Summary: I use PC headsets a lot! as I use them to dictate into the PC. This headset is comfortable and discreet, the microphone is positioned sensibly so you can drink a cup of tea without moving it. the accuracy of the microphone is very good.
Summary: Quite good quality sound when it's working but it's always quite quiet compared to my existing head phones (i.e. I can't turn the volume up as much). I found this headset quite comfortable. Unfortunately, there appears to be some issue with the drivers - I find I have to periodically unplug and re-plug the USB plug due to sound either disappearing entirely or distorting badly. I've confirmed by visiting Plantronics website that updates to the driver are not available.
Summary: Pros: 1. Actual product size is less than the product visuals 2. Length of the wire 3. Plastic quality 4. Easy operation for operating the volume and mic operation 5. USB operation and DSP technology for enhanced audio quality Cons: 1. A Little uncomfortable when wearing the head phones, It's a little tight on ears and size can not be adjustable 2. Most suitable for computer web chats and phone calls but not for entertainment to wear for long hours 3.