Pros Loud with little static - people on the other end can hear me
Cons Large and slow connect to Treo
Summary This is the first bluetooth headset I have used with my Treo 650 that is not only load, but people can hear me on the other end - with relatively good noise cancelling. With others I can hear people well, but they may not hear me well, or we can hear each other well, but bad noise cancelling.
Also it has a relatively long battery life - it was able to last a 4 day weekend with more power to continue a few more days.
The only problem is a slow connect between the Treo and headset when calling (in or out, but this delay gives me a chance to get the headset on before answering).