I already have two Crybaby's (GCB95 and 95Q, which I love to death), but I always have had G.A.S. for a Vox wah pedal, because it has a different tonal character and it LOOKS so deliciously stylish.
I've tried them side by side for a couple of weeks. Here are my findings.
The good: the V847A's clearer/less coloured sound makes it fantastic for clean licks and 70's funk. Cool for some blues too. Looks are super sexy and retro-correct. It has a much better input buffer/bypass than the older Vox wah's (less tonesuck).
The bad: alas, it doesn't exactly sound like the warm old 60's wah pedals. It has a much thinner and treblier timbre, with muddy lows and piercing highs. Which sucks for distorted tones. Really disappointing.
To conclude: I didn't keep it. Will stick to my Crybaby's!
Edit: I just bought an older made in USA V847 (second-hand) and it sounds SO much better and warmer than the new V847a. It's fantastic with overdriven sounds!! Go for the old one!