Sparrow
Really like the sparrow. Quiet with high velocity and very quiet with standard velocity. Really don't hear much difference between standard velocity and subsonic as standard does not crack sound barrier in my area. Usually shooting at hunting lease at 1,400 ft.
All three ammo types cycle easily through all my threaded semi autos.
Have taken it apart for cleaning just a couple of times, easy to take apart and reassemble.
If you really are looking to bring the noise down, give a spray of gun oil in front to "wet" the can.
One caution, if you have not already removed your muzzle brake, be sure to secure the barrel so it cannot rotate in the action. Have seen that happen with (2) 15-22's and its hard to get the barrel re-aligned. The muzzle brake sometimes is really tight.