I bought the Keeley Fuzz Bender, after comparing a range of different high-end fuzz options for bass. Unfortunately I ended up returning it. There is a very distinctive trebly fizzle that I personally just didn't find very pleasing. You can reduce the prominence of this with the Treble control, but it's always there, and if you're wanting more aggressive fuzz tones on bass then it's hard to achieve that with the Treble all the way down. In a band context together with drums and guitar the fizz is much less noticeable, but I really didn't find it particularly satisfying for the kind of bass fuzz tone I like. If you don't think this would bother you or if you're a guitarist though, it is a beautifully robust pedal that exudes quality... so you get what you pay for there. The Bias control is also extremely interactive with the EQ and fuzz controls, so there is a lot of nuance and control there to explore.