Two things:
#1 A tampon is garbage when it comes to stopping REAL bleeding. They do not have the capacity for blood stopping. I carry a couple of tampons in my big first aid kit. For nose bleeds and their intended purpose, they work great. Arterial bleeding, not so much.
#2 While I think this product is AWESOME for wound packing, I don't see it replacing a tourniquet. For civilian use, unless you are miles and hours away from higher medical treatment, I think that the size / weight of this make it impractical.
Here is reality, in the world we live in, you will most likely have paramedics on scene by the time you have stopped bleeding and stabilized. I have no idea what these things cost, and while I really do like it, I don't really see it as a game changer. Simply a way to make packing a wound easier, and maybe more consistent.