Army medic and civilian EMTP chiming in:
I was in when we had both the powder crap, and now the new Combat Gauze stuff. I have used both, (live tissue labs, and in theater.) I strongly prefer the gauze. It worked like a champ.
The powder on the other hand didn't seem as effective, but my skill with it (or lack there-of) may have been a factor. It became a bit of a mess.
Trauma management strategy between military and civilian has always been very divided. For example the use of Tournaquets are almost first line in military, but on the civilian side TQs are considered a last ditch effort.
From my experience a TQ is the most effective care for life threatening extremity bleeding control, and regardless of the environment, it's almost always my first line choice. A properly applied TQ virtually ALWAYS works... unless the artery has withdrawn beyond the reach of the TQ (which is also very rare). I have yet to encounter an MD who disagrees with me.
As far as the use of chemical agents - from my experience, I have found them rarely indicated. They are for life threatening bleeding when you can't apply a TQ. How often do you REALLY see that? A gunshot wound to the abdomen? Think about it... Will Quick Clot fix that? No. The bleeding is from the organs within the peritoneum... Quick clot will NOT reach that. The only thing that will save that person is a surgeon. That goes for most penatrating wounds to the core or neck.
They are expensive, and with economics being what they are, I don't hold it against a fire department for not ordering them.