I have a Tactical Solutions 2211 compensator on mine. It's actually made for their 1911 .22 conversions, but it's a good match for the 15-22. I haven't paid that much attention to noise, so I guess there's not much additional report. It has made a slight change to the muzzle rise. It IS a PITB to clean, however. After 500 or so rounds, it takes a lot of work with GunScrubber or PowerBlaster to get the debris out - the stuff is hard as a rock!!!
If I had it to do over again, I probably wouldn't, but I can't put an A2 flash hider on it in Connecticut; I can put a muzzle break.
2211 Compensator | Tactical Solutions