I've been using this mic for about a year now. I play a solo show on keyboards and needed something that followed my mouth as I have to look at my keyboards (I play 3) occassionally. The thing I love about this mic is that I get no feedback at all, regardless of speaker position or amp power. That's great isn't it? The last thing you need when your out on your own performing is to have to fanny about with volume or EQ settings in the middle of a track.
The sound is rich and makes my voice sound pretty good, which is quite remarkable compared with other hand mics. I also love the fact that with these headset mics, setting up the mixer is a 'one time only job', when it's set, it's set.
Down side:- I wished they had made the mic arm a little more rigid! It drops fractionally whilst performing, and you have to raise it frequently. This, plus the fact that Shure seem to have been undecided as to where the head grip should sit i.e. neck or occipital head area. Neither place works! I used a Nady before, and that was perfect.
Summary:- I haven't replaced it, so it must be good.