This, of course, is where the Beebaa shines. With all of my distortion/fuzzes I own I could easily cut them all out for just the Beebaa. The third mode, what I would call the distortion mode, is quite Big Muffy. I am not sure that I will use this mode in place of my Big muffs (I love the muff and know it very well) but it is certainly a high quality sound. I think the distinction between distortion and fuzz holds here. For those who don't know the difference; the distortion is harmonically richer and covers a broader range of frequencies, the fuzz is a tighter sound, more midrangy, what I call the saw blade effect. Both distorted modes on this thing have more bass than I have ever encoutered in an effect. This is wall-shaking, wake the man across the street bass. Especially if you are playing through a bassy '68 twin with the bass turned up, as I am.
As for the fuzz mode, it is simply incredible. When I first got it I set it up for fuzz, with the sustain on half, a little (1 or 2) reverb on my amp and simply strummed an E major chord. I was flabbergasted. Absolutely no harshness, just a loud, punchy, tight, rich, robust tone. When I started playing with the knobs I was, of course, able to dial in harshness. This can be done with any fuzz. But, in general, when you find that setting on the pedal, with a great interplay with the amp, it is magical, and jaw dropping.
The clean/treble is definitely usable. In the 70's when I don't think there were any pure "clean boost" pedals, it must have been a god-send. However, I have a Zvex Super Hard On and I plan to continue with that. I will not be "up a creek" if the SHO breaks though.
In reality it is three distinct tones in one box; three pedals in one, if you will. All for $250, at least what I paid.