I plugged this pedal in with the controls set flat, immediately i was blown away by the distorted tone available to me. The grunt and mid Boost Switches add bottom end and mids back into the tone, the Tone knob changes the character of the distortion, likely by affecting the treble.
The blend knob does exactly what it says, blends your dry tone with the distorted signal.
The Footswitch is one of the new "non-click" types and is very smooth and sturdy. The chassis is also made from very thick yet light Aluminium.
My only issue (and its a very very small one) with this pedal is the location of the 9V DC In, on the bottom right, next to the instrument in, its a little awkward.
Overall this is a great pedal and despite the price I would not hesitate to recommend this to anyone, you can get a wide variety of overdriven and distorted tones and this pedal has allowed me to achieve the sound I've always wanted my bass to sound like.