I just bought a from my LHBS. I took it home, put a cartridge in it, hooked a QD to it. That was when I made a big mistake. As I was walking over to a keg to test it out, I gave just the smallest squeeze to the trigger. The pressure blew apart the QD in my hand and emptied the cartridge right onto it.
It HURT LIKE HELL. My hand was quite swollen for an hour or so. Luckily no long term damage, and I got lucky nothing flew into my eye. IT does say in the instructions to only hook it to a QD once the QD is attached to the keg. there is a very good reason why. The problem with hooking the QD to the keg first is the co2 in the keg starts venting out until you get the injector hooked to it.
You have been warned!!!
I do have a question concerning the QD. It came apart but doesn't apear to be damaged. The three pieces go back together fine. Has anyone taken their QD apart and used it again? do you think I should attempt to use this one, or chalk it up to lesson learned and toss it?