Excellent battery life, easy to use, clear audio... however, the earhook is very tight and not flexible at all. I am a little over average size for an American male and to me the earhook is somewhat uncomfortable, not enough to be painful but enough to be annoying, especially if worn for a long time (you will find yourself wanting to pull it off as son as you finish your call). I cannot imagine a very large person being able to use this at all, so if you are a 6'6" linebacker you might want to look at something else.I had a SEMC bluetooth adapter similar to this one a couple of years ago and it was the same story... I am puzzled as to why Sony Ericsson persists in making these stiff, unflexible, too-small-for-the-average-American-male earhooks... you'd think they would have corrected this design flaw by now. As another reviewer observed, the only part of the earhook that is flexible is the very bottom, which does not even come into contact with your ear.