I thought I'd give the new DonnyFL Fatboy a try. I like the idea it can be set up for any caliber from .177 to .30, and while it seem to have good volume, it doesn't sound as quiet as other DonnyFL moderators I have. This is probably due to the shorter length. While it is about the same or maybe a tad quieter than the stock Moderator that came on the LCS SK-19, it is shorter. I added the air stripper thinking that might help with muzzle creep shooting in full auto, but it really hasn't made much difference at all. It's not as quiet as the Huma Air MOD40 or the DonnyFL Ronin I have tried on it, but it is still backyard friendly, and quite honestly, looks BAD@$$ on the SK!
Bottom line, is it worth the money they are asking? If you are looking for sound attenuation, not, there are better sound attenuators available for the same or less. If you are looking for that BAD@$$ Tactical Look, then maybe, that's really up to individual taste! I do like the looks in this gun, but if I want to be more stealthy, I'll be going back the the Ronin or MOD40 from Huma Air!