When you talk about the classic fuzz, you probably mean the sound of the legendary fuzzface in most cases. Used with a clean amp, this pedal produces a quite nice distortion (due to the germanium transistors it is never as annoying as various other distortion pedals). However using it with a already distorted sound, it really shines like the sun. This is the sound you know and love from Jimi Hendrix, the early David Gilmour and Eric Johnson.
The Fulltone 69 Mk II delivers exactly this sound with Fulltone-typical quality and reliability. There are also extras such as the input knob (e.g. prevents the pedal from gain pumping because of too powerful pickup signals) and a bias trimmer, influencing the sound, which are welcome features.