I just got the Motorola HX1 and i must say it kicks a**. I tried the first 2 Jawbones and they were crappy for the price. People could hear me pretty clearly with the JB2 but i could not hear them at all in a semi noisy environment. I hated not being able to turn up the volume as its automatic. I was tempted to try the Prime but i did not want to spend another 130 bucks and be disappointed again.
So i went with the HX1 and am glad i did. It has dedicated buttons for all the functions which makes it much easier to use. Not having to memorize a bunch of different push combinations is great. And being able to charge it with a micro usb means being able to just carry one charger that will work on my Storm and my BT (connecting the JB is a pain). Plus you don't have to worry about making sure the JB is always pressed against your cheek (if its not it doesnt work for sh*t).
Just my .02

