The main problem is function as volume pedal because its very short range, no matter how you set the volume. If you want to operate the pedal from total silence to maximum volume, you will feel it like a switch, I mean it opens up in a very short distance when you press the pedal. If you try different setting form the "Min volume" rotary button you will find that you can't obtain silence when the heel is pressed and pressing toe will increase in some degree the volume, but not too much.
Wah is very usable, with good sound and good range. The noise generated by the wah is negligible, you won't feel it.
Pedal seems very solid.