The M22 is doing great and sounds excellent! I actually just acquired an M-25 as well, it's really nice with the Gold plated input/outputs. Also, it's Class AB so with higher power demand it switches to Class B for 120W output and cooler operation. Love them both! Also, no issues with the amp sitting on the speaker, these HPM"s are very stable with little to no vibration, previously I ran a Dynaco Tube amp up there with no issues. Also, I've tried moving the speakers around a bit but i'm in a fairly small area so the sound changes were minimal.