The link is at the bottom of the page.
Not just any fuzz, the FuzzFace. The design is so simplistic that is just doesn't like to work. Now as for sounding good, there are stories or famous musicians stockpiling every original FuzzFace they could find that sounded good. Just like playing a bunch of cheap guitars with shotty quality control to find the one good one. I want to say it was Eric Johnson, but I could be wrong.
I would suspect that is the reason Jimi had his FuzzFace modded. He probably like the overall sound, but realized something wasn't right.
After building a FuzzFace I actually felt like Fulltones '69 was money well spent.