I have both and they're actually different enough to justify having both. The Germanium is more subtle, with considerably less gain and a more pronounced octave to it. The sound is more pronounced in the mids. If you want a more "vintage sounding" fuzz, then this is it.
The Silicon is a monstrous, horrible (in a good way) beast with deadly amounts of gain. This one has more of an over-the-top industrial style gain! If you want your fuzz tone to slay the first ten rows, then this is perfect!
I love both of them and love the individualistic character of each one. Josh is a friggin' genius (and one helluva nice guy)!
