EVERY SINGLE TIME you turn it on, you have to listen to a stupid, cheesy sound effect and a voice that tells you about the battery level and all bluetooth connections.

Best I can describe is that they mask the constant hum of air-con or road noise, but a lot of mid-range noise make their way in (like loud voices, loud cars, buses)

When it works they say my voice sounds good but other times it doesnt work at all.

All that weird head-voice instead

Superb integration with BT600 and good voice clarity

" moment, but thanks to the stupid voice prompt on the Plantronics you're losing at least 4 seconds of sound, and with it any chance of hearing what they just said over the intercom.

But the call quality is excellent, and callers say they can hear my voice very well and noise cancellation works well