I have the Morley Bad Horsie II and the Ibanez Screaming Demon, both are switchless wahs, the Bad Horsie II has a contour wah as well as the Bad Horsie wah, and it is my favorite, the Ibanez Weeping Demon has a lot of adjustments, but is more for Jazz, not that great distorted, the Bad Horsie II rocks clean and distorted.
I am frustrated by the other wahs, they are hard to turn on and off, and the pots wear out, the electro optic pedals don't wear out I have Morley Little Aligator Volume Pedal which I really love, and its still working after many years, I have thrown away every passive volume pedal because I have worn out the pot, the same with the wahs with pots, they wear out after a while.
No. There is an internal buffer always on.
I am biased, didn't like the Bad Horsie at all; found it very susceptible to noise when off, and noisy when on, didn't like the tone, etc.
The Silver Machine is dead quiet, has a better buffer, and has far more tonal range.