China Drum (or The Drum) used it a lot on there last album Diskin.

I like to use it for pitch shifting: moving extended chords up or down a whole step or for sending notes I’m bending up to up an octave during a solo. This thing sounds nice with a delay after it in an effects chain (not loop).

Use with caution, I know of several PAs that have had there top end speakers (not double driven) destroyed by this device....Oooops, never mind !