I used this daily for 2 months and had nothing but trouble with it.Fit--I have small ears and used the small ear bud but it would not stay in my ear and always sat on the outside of it. It finally fell out of my ear and I lost it.Pairing--No trouble in the actual pairing with my Sprint Treo 755p, but it disconnected frequently and then would reconnect in the middle of a phone call causing me to lose momentary connection with the person I was speaking to. There was no rhyme or reason to it either. It didn't matter if I was close to the phone or far away. It would just connect and disconnect at random.Sound--Anyone I was talking to would know I was on "the headset" because there was static and my voice would fade in and out.I will say it was easy to use, I liked the position of the connect/disconnect button and the notification beeps worked well. I don't have experience with any other headsets but the battery life seemed to be good for this.I've always had great luck with Plantronics so I was disappointed, but I was especially disappointed after seeing this got 4 stars here on Amazon and it was such a terrible experience for me.