The Bottom Line: Rumor has it that the Jawbone may have slightly (very slightly) better clarity, but isn't worth the bulky size to me. I love the Z9.

I've been using the Motorola H500 for about a year. It has a little trouble staying on the ear, but my worst issue with it recently is this: I have a 30 minute commute to work on an interstate where I'm on the phone every drive. I had to press the headset into my ear in order to hear over the road noise (and the road noise wasn't TOO bad - I drive a 1998 Acura 3.2TL). I needed a louder headset.

I have a Samsung WEP and it kills my ear - so uncomfortable.

Models I researched: Jawbone, Plantronics 655, and BluAnt z9. I figured the noise-cancellation feature of these 3 headsets would be useful - I'm a technology consultant to Fortune 500 companies: I don't always want them to know that I'm attending a teleconference from my car ;-)
I went to Best Buy today ready to spend $100, especially in light of the 30-day return policy. The very knowledgeable sales guy had owned all 3 and highly recommended the Jawbone due to the incredible call clarity. There's only one reason I didn't get the jawbone is its SIZE – I wear a collared shirt with a chest pocket every day and I keep my headset in the chest pocket. The big jawbone would look awkward protruding from my pocket, whereas the Z9 is quite small. Paid $99 at Best Buy for it.

So I immediately went to my car and paired it with my Dash – no problems. All of the normal buttons do what you would expect them to do. Unique things to the Z9 – if you push the big button in mid-call it turns on 'maximum voice isolation (noise cancellation)' and, by the way, there's a man's voice that comes across and says 'maximum voice isolation'. You can also pair it to 3 devices. Check the owners manual online if you're interested in this – I'm not interested so I didn't read about it.

So I called my parents on the drive home as I usually did with my H500. They said I was very noticeable clearer compared to my old headset (they're in their 70's, so it must have really been better!). When I got on the highway at 70 mph they said it sounded just as good as when I was stopped. I was NOT using the maximum voice isolation (noise cancellation). I tried the maximum and Dad said 'you sound a little tinny, but good'.

Charging – via a proprietary connection – a USB cable and A/C adapter come with it. I'm really bummed that it doesn't have the mini-USB connection that my H600 had.
Fit and comfort – it's really, really light. The clear plastic piece that goes around your ear is a bit flexible, so it's comfortable (and I WEAR GLASSES). The part that goes in your ear is the typical round speaker, but the outside of it I about 2mm thick and gel-like (unlike many that just have a rubbery-band around the round speaker). It is NOT a big gel like the Plantronics though. I expected that I would like a big gel like the plantornics, but the Z9 is SO COMFY that I'm no longer thinking about other headsets. Doesn't move on your head (unlike my H500).

Quality – Great, but not perfect. On the highway, I pushed the volume up all the way and there was a little bit of distortion. Don't let it turn you off from the headset though – it was present, but not too distracting (I'm a musician with a discerning ear).

Range – fine. I never move beyond 20 feet from my phone anyway.