LM324 oddities/quirks

[Mark Hammer]

In the Stompbox Cookbook, Boscorelli incorporates an LM324 in his Distort-o-Matic IV design.  He cascades all four op-amps in the chip, each configured as unity-gain, and notes that it:
"takes advantage of distortion introduced by the LM324 on audio signals greater than 3V p-p.  One type appears related to the 324's low slew rate; the other to crossover distortion in the output stage of the op-amp."
Have any of you ever built the Distort-o-Matic IV or simply used the LM324 in this way?  And if so, how would you describe the resulting sound?