I've been using Dunlop - Kirk Hammett Wah since years on stage and in studio. It's a kick ass pedal and good rivalry to compare with.
So comparing to it, John Petrucci Wah has much wider sweep with focus on the lower end. In reality it goes so deep that almost kills guitar signal, making it very muffled and non audible. It's cool but you need to know how to work with that. You can get ear catching emerging effects while going out from that "abyss" into your licks but occasionally shifting pedal too dip during solos just kills your notes. So it takes time to get used to it. But Kirk's Wah is not capable of doing that kind of thing at all.
Overall tone is a bit more cold and modern sounding compared to Kirk's wah (that one is like fried potatoes :D ). Yeah, it has it's own taste. I can't say weather it's better or worse, it's just different.
EQ hidden inside, I love that. Yeah, might be not that convenient to adjust, but in live show occasions, it's the best. Nothing sticks around, no way to mess up your settings. I tweaked EQ to my taste and got exactly what I need from that pedal.
Blue light on the sides, simple and must have feature. Something that Kirk's wah doesn't have and that caused couple of incidents during live shows on my side.
So all in all, I like this wah a lot, great sound, usability and smart features inside. It replaced my old wah in the pedal board.