The Whammy can do monophonic bends(one note at a time) up to 2 octaves up or 3 octaves down. With the harmony modes you can have a bend go from below the note to above the note. (for example toe down = octave up, toe up = octave down.) And I’m not 100% sure about this, but you can’t stop in the middle of a bend and leave it there and keep playing at that pitch.

The HOG can do polyphonic bends (single notes or chords) up to 1 octave up or 1 octave down. You can’t go from up to down in one bend, it’s either up or down. You can stop mid-bend and keep playing at that pitch. There’s a lot of other cool stuff though, like all the pitch voices so you can get organ sounds, plus a filter, as well as an attack mode for swells, as well as FREEZE.

The real whammy killer though is the EHX Ring Thing. In addition to doing ring modulation, it can do pitch bends from two octaves down to two octaves up, and it offers the advantage of polyphony like the HOG.