I'm an admitted wah junkie and I've played many wahs over the years. I currently own a 95Q wah, a Hammett wah and a CAE wah. And I'm really looking at purchasing either a Bonamassa or Cantrell wah as my 4th (leaning more towards the Bonamassa as it has a halo inductor).
For playing live, I always use my KH wah. IMO, it's the most balanced pedal throughout the full sweep of the rocker pedal. Also, it does not get shrill in the toe position. It is for my purposes, the best wah tone.
That being said, a very close second IMO is the CAE wah. It's definitely the most versatile wah I've played. True bypass, two fasel inductors which are fully adjustable and an included boost line/ line driver (which can make this wah really loud) are really what sets this thing apart from the pack. If you don't know what you want in a wah, this would be the one to get as it can really do it all, from clean to high gain. Dunlop really hit a home-run with this one.