I previously owned a Plantronics 645 which I liked quite well, but it came time for a replacement. I typically only use the headset in the car, so I was looking for one with good noise cancelling features. After using this headset for about 2 weeks, I received so many complaints from the people on the other end of the calls, that I had to stop using the headset and use my handset directly - just so they weren't completely annoyed.I really like the fit, feel, and weight of the unit, and the incoming sound quality was always excellent. When I was stopped at a traffic light, outgoing sound was very clear and nice, but unfortunately even the slightest road noise was a big issue.I really wanted to keep this headset because I still have some older accessories that are compatible, but unfortunately I will have to return it. With the DSP technology and Audio IQ I expected this headset to be better than my 645, while it ended up being much worse.