I bought this instead of the Bass Big Muff Deluxe since I play both guitar and bass (and the Sovtek had the same blend function as the bass one).
It is all, and more, what I've ever wanted from a big muff... It's bassy, but at the same time you got the wicker, tone and the mid freq. to dial it in real treble-y. I love this pedal on guitar, I haven't found a bad tone yet, but it really shines on bass for me and it is my main bass fuzz atm.
The blend is absolutely amazing, I like to keep it on 50/50 or 30/70 (clean/fuzz) in order to get enough of that punch through. But, the thing is, when you're thinking "ah well, now the fuzz is too much in the background" - and the sound gets muddy; hammer that mids-switch!
So even with the tone at like 9-10 o' clock, you can dial in your mids beautifully without losing any low-end. There's even an input for an exp. pedal which I haven't tried yet, more experimenting to be done for sure. But I love it.