The headset is good so far. The phone I am using with it (Sony Ericsson T610) right now sucks. You don’t really know how good or bad a phone is until you use another one in the exact same places and get totally different results. This time I used the T610 on my trip up from NYC to Kingston. On the train my Treo normally backs out allot, so did my verizon phone. In the cab from the train station I am usually able to make calls, and sometimes have spotty service. With the T610 I had almost no coverage at all on the entire trip. In the cab from the train I had no signal until I was 5 minutes from the office, and our office has a T-Mobile tower in the same building complex.
The headset worked well when I had good cell signal. No complaints from people about voice quality. I probably wont use the headset that much since the phone sucks. I am sticking with my Treo 600 for now. It actually gets a signal. Palmone, please put bluetooth on the Treo!!!