As well as a motion sensor, the Electro-Harmonix Slammi boasts three octaves of pitch shifting, plus four controls, either side of the pedal: dry volume, for blending shifted and dry signals; max bend, for setting the interval; a bend up/down button, and calibrate button for the sensor.
"The Sammi offers speedy polyphonic tracking and convincing tones"
That means more flexibility than the Slammi's rhyme-sake, and the sounds are on a par, with speedy polyphonic tracking and convincing tones.
Accessing the controls is pretty fiddly, though, and we found the sensor too sensitive; it picks up every slight foot wobble, so it's hard to get a smooth pitch bend. An acquired taste perhaps, but a commendable alternative pitch shifter.