I used these headphones with the HTC Advantage 7501 and it worked very well.  The sound was very good and the controls worked as advertised.  However, the ear pads come off easily and after only one week I lost one.  Motorola said they don't sell the ear pads separately and apologized for the inconvenience.  They were a bit uncomfortable with the ear pads so obviously without one the headphones were unusable.  Seems like a design flaw to me and I feel a bit ripped off.  If you do decide to purchase this product I would immediately glue them in place.