so fwiw, one guy's opinion and ears, the huma-air mod40 moderator is quite a bit softer sounding than the stock leshiy 2 moderator. no apparent shift in poi.
specifically, this is the leshiy 2 long, 350mm barrel, .22 slinging 18.13gr jsb pellets at the factory tune (i am assuming ~940fps)
i have heard others advise they didn't see much difference, so i wanted to note that this is just my experience with my example. to be honest, so much air came out from around the oem shroud that i wasn't even sure i had installed it correctly, and although egw told me this was "normal", i am still not certain these gaps don't vary and thus the amount of sound coming from it may be different too.
how much quieter? hard to say, but oem wasn't much quieter than the heavy duty staple gun i use at the shooting ranges, and now it is quiet enough that i am not concerned. i will try to borrow a decibel meter to do some sort of comparison, just for giggles since i understand these sorts of tests are less than accurate. so far i have only shot it will the full stack and no empty sections, but i may experiment with different configurations.
unfortunately, i cannot compare it to a DonnyFL or any other silencer or rifles, so i cannot say if it is better or worse than anything else out there.
edgun pic time...i really like that the leshiy 2 is adaptable fill several roles with a quick configuration change. this is why i like good quality qd mounts.