Im the happy owner of a stock 15-22. I recently added a norwegian Atec cmm4 rimfire which I havnt regretted. The muzzlereport is "drowned" by bolt-mechanics and brass hitting the concrete floor. Accuracy is same or perhaps even better than before - only shot 50 rounds so far.
The moderator is aluminium, very light. It is modular and easily taken apart for cleaning without use of tools. I think it looks fantastic. Thread is 1/2x28, so no use for adapters.
Optics is a cheap Weltor 4x32.
EDIT: Forgot to mention that I use CCI standard which is a perfect round in my 15-22. Accurate, reliable and subsonic