Hrm, it's a tough comparision - or at least not directly comparable. The range of the pedal mechanisms are very similar (Behringer has a really snappy spring fyi). I would say that the Morley has a slightly wider range in terms of the wah effect itself. Personally, I don't like that - harder to be precise IMO if your not just stomping away on it. Regarding the range of sound that can be affected, it's the Behringer definitely. The Range knob + Q + Fine Tune + boost & level really allow a ton of control over how you scoop the sound. You can pretty easily dial in the percussive funk sound from the Morley dual bass wah. Like the dual bass wah, it works perfectly with a 6 string bass (low B is fine, f# is less than splendid - may just be me).
Behringer is a battery hog. New 9v will give you at least 3h. Get a Powerall or something. I use the 1spot and it's completely noiseless (switching supply, no transformer).
I'm not big into the 70s funk (my wah usage is very Rage specific), if I was I'd probably stay with the other pedal. The Pro 2 metal housing alone ensures that it'll work nearly forever while withstanding abuse. As wah isn't an intregal part of how I play it's hard to justify the $$ for something (to me) more gimmicky. Considering that I also like the sound & control of the Behringer more, it was a no brainer about which one is more appropriate for me.
My advice, if you want a wah and you KNOW you want a wah, get whatever it is that you want (Morley, Bawls, etc). If you're thinking about a wah or could work one into your gig, get the Behringer. The sound is on par with something boutique, but you don't have the 'I just spent $75-$200 on this thing so I really gotta use it' mentality
Hope that helps a bit. Like I said before, I've never disliked Behringer, but because I take my music very seriously I'm very careful about the money I put into my gear. The $30 price tag isn't indicative of the sound quality.
Also, don't buy this pedal used. No clue about what happened to it before you. It is plastic (though pretty tough) and plastic like aluminum will stress fracture.