I got mine just after I had gotten back from my second deployment. For a few months I had been hauling around a STOMP, and fucking hated it. Then I moved to a TC3 bag, which was AWESOME for dismounted patrols. The reason why I liked it so much was because it looked nothing like an aid-bag. Most of the time, I had other soldiers from different units asking me how much ammo I was hauling inside it. They never had the slightest clue that I was a medic.
When I finally got my M9 bag, I amazed at how much you can stow away in it. Its still lightweight, the straps are comfortable (to me at least), and its not overly obvious that its an aid-bag.
Since these pictures were taken, Ive almost doubled the amount of gear to it (stethoscope, BP cuff, glucometer, suture kit, epipens, more IV and airway supplies, etc, all of which fit perfectly once you move around the velcro pouches), and now I keep it in my POV as a jump bag. Dont get me wrong, this bag rocks, but its not the cure-all. Im still shopping around for a decent priced STOMP to fill the MASCAL/resupply role, but its definitely my favorite bag Ive ever had.