With the right ammo, it's awesome. Definitely not .22 quiet, but still pretty darn good.
I can shoot 115 grain standard ammo with no ears and no ringing afterwards- but there's no pretending it's quiet. I had some old Master Ammo (?) 147 grain subs that were great. Just sounds like a thunk-ssshhh. I wouldn't let loose with it in the backyard, but if I did it wouldn't draw too much attention.
Cleaning isn't a big deal either- I thought it was funny that the other company advertised their "Click to Assemble" baffle stack- the Guardian is the same, they just don't advertise it that way.
Glad to hear it. I have some of the Federal American Eagle "Supressor" ammo that I'm going to use with it and my XD.