had them both..
returned the Jawbone after 3 hours, and got the 975
LOVE the 975; I hate headsets that just get jammed in your ear, but I can wear this thing for 5 or 6 hours without taking it out..Damn Jawbone is almost impossible to fit properly, the buttons are HORRIBLE, and the sound was robotic..
the jawbone gets LOTS of horrible reviews, but, I haven't seen many on the 975. I've had at least 15 different bt headsets over the years, and, as far as "mono" in the car types, this one is the best for sure...As far as stereo bt is concerned, that is a whole different story..