I'm giving the Blueant Z9 a whirl. Here's my impressions so far.

The pluses:
- It's plenty loud. The loudest headset I've used to date
- It cancels noise well. I have frequently used this while driving my vintage BMW with a modified exhaust. No complaints on the other end. This is impressive as were I to use the handset directly with the engine running, callers frequently complain about background noise.

The minuses:
- It always feels as though it's about to fall out of my ear. It never actually has fallen out, but the feeling that it's about to leave my head is distracting.
- The pocket clip is a joke. It looks very dapper when you wear it clipped to your shirt pocket. The first day I tried this, it fell off 3 times causing me to have to go searching for it. That was it for me and the pocket clip.

So, for this BT headset user, it's OK, but still not my Holy Grail (fits my ear well, loud, good noise canceling, and easy to carry when not in use).