I grabbed one of these used just recently & on it's own...it's kind of the typical Boss distortion. Neither the most dynamic or the most realistic/tube-like sounding/feeling distortion. But it does seem to be a marked improvement from a lot of their older units that I've owned (nearly everything from the early 80's on). Typically Boss units (to me) always seemed overly harsh & artificial sounding in the upper mids and just gave off a grating "feel" & tone that did not make me want to use them. Their new Power Stack seems to mostly eradicate that problem & this unit is maybe a notch or so below that one. If I keep the TONE knob below 1:00 or so and the BOTTOM knob at about 2:30-ish it gives you a massive sounding grit, w/a ton of low end, without being to muffled. If either of those two creeps up higher than that. It starts to get either harsh or farty...depending on which knob is cranked.On it's own, I might not be super impressed...but I'm currently using it in conjunction with the Boss Power Stack in a split setup with one pedal going to one amp and the other pedal going to a 2nd amp and it really shines in that setup. Both are set to about 3/4 of the max gain & the Power Stack gives you the beefy mids, while the MD-2 provides a ton of low end & some upper-end sizzle. Both are set to less than full gain & goosed w/a overdrive for solos. So far, it seems like my favorite setup that I've had in many years.I gave it high marks for value & quality, just because Boss pedals are always durable and reliable & thus a great value for the $. Probably not the single most versatile Dist pedal out there...But for my setup it works excellent. If it was broken or was lost...I might look at other pedals...but I would definitely keep it in the running when looking for a replacement.
