Not having much luck with past Bluetooth headsets, I was hesitant to give up my wired headset.  But, all in all, I am pleased with the Cardo Scala 700.  Occasionally, I do get quite a bit of static but that tends to be during the initial stages of the call while dialing.  Once connected, I rarely get static unless I am talking with my girlfriend <g>.  If I am in a noisy environment, people sometimes have a hard time hearing me but that is infrequent.  I have had some difficulty keeping this working with my Treo 700wx but I have never figured out if it is the cellphone or the Bluetooth headset.  Usually, if I "refresh" the headset on the phone, it will work fine once again.  The ability to easily switch it from one ear to the other without any hassle is also nice.  I am very impressed with the battery life.  I've had this for a month and despite sometimes not charging it for a couple days, I have never run out of juice.  Most importantly for me is the comfort.  Once I figured out how to adjust the ear band so there are no pressure points, I don't even realize I have it on; that's how light it is.  In fact, a couple times it has been on when I laid down in bed at night and I didn't realize it until I rolled over and put that ear on my pillow.  This is probably an odd comment but it is so lightweight that it almost feels cheap; in the same way as if you were to hold a cheap $5 Kmart Blue Light Special watch in one hand and in the other hand, you hold a Rolex, which feels more substantial.  Still, I'll take the lightweight headset anytime.  If I were to buy a Bluetooth headset as a gift, this would be the one.