I have an HS 850 that works ok with my TMobile 7290. Sound quality in and out is understandable, although in noisy enviornments, I have to hold the unit to my ear to hear (which kinda defeats the purpose of hands free...). I use the BB as my office phone, so I often use the headset for several hours a day. Although there is no discomfort with the headset, I always feel like it is going to fall off, and since I wear glasses, I sometimes have to adjust the fit to hear well.

I have thought about either the Plantronics or Jabra with a piece that goes into the ear, versus just sitting on top...