From playing around a bit, I can get a good fuzz sound but can't say it can exactly match a fuzzface type pedal. I've been meaning to get around to actually A/B'ng with my Foxrox Hot Silicon, which is very close to the original silicon fuzzface. As far as the response rolling off the guitar volume, the Axe will clean up in a linear fashion but it's not the same as the real deal IME. The fuzzface to my ears has a distinctly different overdrive/crunch with the guitar volume rolled back. In the sweet spot, in conjunction with a somewhat overdriven tube amp I can go from a "Little Wing" tone to "Foxy Lady" with just the guitar volume. Now, I love how the Axe responds to guitar volume and dynamics, but in this case so far I can't duplicate the FF. For just the all out fuzz tone, the Axe can get close enough for my purposes.