I'm really not much of a lead player in the traditional sense. I'm just not all that fond of shredding aside from the fact that I'm not terribly good at it. I play my wah a bit more like Adam Jones, I use it to surf, Find the harmonic I like and ride the wave until I feel like changing it up.
Having said that, I had a band mate that had a handful of the dunlop signature wahs, he had an original, a zakk wylde, dimebag darryl and slash wahs. My favorite of his was the dimebag because it was so customizable, and I really hated the zakk wylde version, it was all low end and sounded cardboard thin.
Myself I use an original crybaby I modded myself, I wish I knew where the website was that walked me though it, but I basically swapped out the switch for a 3pdt, added an LED to let me know it was on, and bypassed a buffer section.
You can see on the upper left on the PCB where I've got a red and orange wire braided together bypassing where a resistor used to be. And a few other resistors were desoldered and removed. I don't know exactly what it did, but I've side-by-side compared it to an unmodded pedal and it just sounds a bit more... hendrix-y... i guess. I like it a lot, and its become the staple of my Wah work. Never need to get another wah.
having said that. the built in Wah's on my GT10 are pretty amazing too, some of them I like better than my modded pedal and have lately tended to use them more. Its especially nice because you can customize the sensitivity and range of the treadle as well. That's not something you can do with a traditional wah.