It's not a super high gain distortion. More of a nice crunch. Very crisp.
On mine, I can't turn it up past noon too much, else it starts to gate the sound. Very odd...but this is a very, very different kind of circuit with the transformer doing the job of overdriving things. Need to look into this though.
One thing I found is that it works really well with a boost behind it. Something like a Harmonic Perculator works fantastic...which is a Germanium style boost. Sounds freaking awesome once you add that.