For what it's worth, I built a Demo Tape Fuzz and it ended up in my recycle box - it had a really nasty, unnatural note decay/breakup characteristic, that I was completely unable to get rid of.
Shame really as otherwise it was pretty good - had a great tone circuit - if it wasn't for the decay, it would have nailed Paul Westerberg's guitar sound.
Still there's prenty more to try, so have fun!