I purchased the HS810 to use with my Motorola V600 on T-Mobile. I have been a huge Motorola fan since the StarTac and been very happy with their products. I have used a variety of corded headsets from Motorola, Plantronics and Jabra. Was very skeptical about the HS810 from pictures and did not think it would be comfortable to wear. What a product! The headset takes a little getting used to on the ear, but it is totally amazing. Paired with my V600, the sound quality is perfect. My longest wear was 1 1/2 hours in the car and could not tell it was on. Some reviewers have had problems with other phone manufacturers; my boss uses one with the Treo 650 on Cingular and he is very happy with it. I use headsets alot, and now to be totally wireless is awesome. My headset cord was always getting caught in my seatbelt or on my coffee cup in the holder in the car - not anymore. The headset paired up with the V600 immediately, and both work seamless together. The V600 has voice dial for names in the phonebook and nothing is better. Will never go back to corded earbuds.