I've recently used the Moto HS820 and the Jabra BT800. Here's my take on those models
Light, almost don't notice it's there.
Fits snugly againest your ear.
Comfort, you almost forget it's there. (repeating theme)
Simple to use - one button does it all. A lot to be said for simplicity.
Hard to hear. Had to use full volume and concentrate to the other person. Could present a problem in high noise areas. Often had to press the ear piece hard against my hear in these situations.
Note: Make sure you fully charge it before using it or the person you are talking to may complain of echo. Fully charging it resolved this issue.
Feature Rich - rings and/or vibrates!
Can make calls from the headset using the headset to people that have called you.
Caller ID (number only) appears on the headset.
Good speaker and easy to hear the caller
Heavy. (ier than the Moto)
Fit - Some time pulls away your ear when you are bending over side ways.
Comfort - Heft made it uncomforable to wear for long periods of time. (big issue)
Feature Rich = complicated to use. not always good. Basically my non techie friends could use the Moto how they would never use this one.
Answer button not intuitive. I think it should be the big button but it's one of the smaller ones.
Overall I like the weight (light) and simplicity of the Moto over the heft and rich features of the Jabra. the jury is still out on which I will ultimately chose but I think it might be tilted towards Moto right now. Good luck. This is a fun problem to have.