Update from my previous 5 star review:
Power jack broke after being plugged into maybe five times.  I baby my gear.  The build quality on this pedal is garbage.  It happened just after my Amazon return window closed.  I guess I'll buy a part, get out the soldering iron and hope for the best.

First review:
How can you not like this pedal?  If fuzz is what you want... fuzz is what you get.  Listen to some YouTube clips of this pedal if you are not familiar with what it does.  If you want that sound, this is the only option.

FWIW, I tried the Nano Big Muff Pi, and found that I preferred the big one, even though it is a pedal board real estate hog.  Supposed to be the same circuit, but I kept picking the big one in blind tests.  The Nano sounds great too... just not that specific sound I expect from a Big Muff Pi.

Also sounds great when used in a bass rig.  Haven't tried the Bass BMPi (made for bass), so I can't compare.  I just know the guitar BMPi handles a bass nicely.
Update from my previous 5 star review:
Power jack broke after being plugged into maybe five times. I baby my gear. The build quality on this pedal is garbage. It happened just after my Amazon return window closed. I guess I'll buy a part, get out the soldering iron and hope for the best. First review:
How can you not like this pedal? If fuzz is what you want... fuzz is what you get. Listen to some YouTube clips of this pedal if you are not familiar with what it does. If you want that sound, this is the only option. FWIW, I tried the Nano Big Muff Pi, and found that I preferred the big one, even though it is a pedal board real estate hog. Supposed to be the same circuit, but I kept picking the big one in blind tests. The Nano sounds great too... just not that specific sound I expect from a Big Muff Pi. Also sounds great when used in a bass rig. Haven't tried the Bass BMPi (made for bass), so I can't compare. I just know the guitar BMPi handles a bass nicely.