I recommend the HIGH IMPEDANCE version of this model for any location in guitar rig signal path. This is very a solidly built unit and a perfect size and weight. I tried it in my guitar setup, for volume swells and to control the overall level being sent from my pedalboard to the front end of a Marshall Plexi-style non-master volume tube amp. I A/B'd it exhaustively vs the HIGH impedance version of this same pedal, and strongly preferred the sound of HIGH impedance model, even after a buffer. My signal path is Tumnus (with always-on BUFFER) overdrive, into Rockett Dude overdrive (true bypass), then the volume pedal then delay/reverb, into the front of a cranked up amp attenuated after the speaker output. Putting volume pedal after dirt but before delay and reverb lets the "tails" of the time-based effects decay naturally when you cut off the signal with the volume pedal. According to Boss' information--and the "prevailing wisdom"--this LOW impedance model theoretically is supposed to work better than the HIGH imp one after a buffered pedal. But in my rig, my tests showed the LOW imp version sounded a bit duller than the HIGH impedance one, even after the buffer. My rig's frequency response and the overall gain structure of the amp were slightly altered by the LOW imp version when compared to having no volume pedal or using a HIGH imp one. You often read that HIGH impedance volume pedals after a low impedance output pedal (like the buffer on my Tumnus) can suffer--the volume taper of the pedal supposedly gets less gradual, more touchy and sort of on/off. But my tests gave a different result. The HIGH impedance version still had a very usable taper, and smooth volume swells were no problem. With the superior sound of the HIGH imp version, that's the one I kept. The size of this pedal is ideal. Not too huge, but still large enough to feel natural. The heavy, metal construction helps keep the pedal in place on the floor, and not sliding around.
Manhattan slide guitarist