I'm very impressed. Using with an MIA jazz, Empress Compressor, Sonic Stomp, Genzler Magellan 800 and Bergantino AE410. I love the tone before, but the M81 is incredibly clear, dare say budget Sadowsky. Warm, bold and smooth. I love the mids scooped on this pedal. Reminds me of the heyday of the higher end SWR/Eden/Trace Elliot sounds. I get to try it on stage Friday night. Don't overlook this pedal, definitely worth a try.