Impressions:
My favorite position on the toggle so far is up -- the treble-emphasis mode. The bottom bass-emphasis mode is next. The middle mid-emphasis mode seems to voice the pedal more closely to a distortion than a fuzz. That might be useful in a lot of setups but it's not the sound I want from a fuzz.
I can't tell that the mids control does much. Maybe mine is broken. Maybe my amp is already too mid-heavy and it doesn't matter. Maybe I'm not cranking my rig loud enough to notice it. Maybe my ears suck. I'm not super-concerned unless it's supposed to be dramatic and mine is actually broken. It sounds good as it is.
The clip doesn't highlight the real thickness of the sound (it was mic'd straight on the voice coil). It's wooly big muff but without the quirkiness. It does nasty spitting guitar and thick synth-like leads without changing settings on the pedal.
It responds to different attacks. I use a compressor a lot with distortion to get more sensitivity without overdoing the gain. That works with the Colossus but I think I like it better with the gain higher and the compressor off. When the compressor is off, the pedal reacts to dynamics and it's easier to do talking guitar.
It positively
wants to be turned up and let loose. The lower-gain sounds are cool but it seems to hit it's stride with the gain up, playing with a lot dynamics, and really using the guitar's volume and tone.
There is a
ton of output boost on tap if that's what you want. Unity level with my clean sound is at about 9
0. I think you could blast the front-end of an amp easily.