After watching Mike Martin's very informative PX-560 video, I started to shop for an expression pedal.  The three listed in the PX-560 manual on page EN-10 (Roland EV-5, Kurzweil CC-1, and Fatar) have really mixed reviews online.  It seems the Yamaha FC7 and the Moog ACCEP003 EP3 are the most favorably rated.  I also see some pedals are high impedance while others are low impedance.  I can't find where the PX-560 manual addresses this requirement.   In your experience, what pedal(s) works best w