Probably the best Wah pedal about. Sounds great clean, or dirty which has plenty of guys to it. Worth paying the extra for over the regular Dunlop Wah. I liked this over the JD Classic also, I guess it's just horses for courses though.
I purchased this when it was on special offer, to replace a tired old standard Crybaby I used to use. I really enjoy this pedal, the sweep and frequency response make it a lot more vocal sounding than the standard wah, which always seemed a bit thin to me. The top end is not as harsh as the standard crybaby and very musical, though the trade of to this is that in the heel down position the sound can drop away quite dramatically, as the low end sweep on this is very low, well below the usual mid-range honk of the heel down position on standard wahs. This could lead to you getting lost in the mix a bit, but to be honest you don't tend to play with the wah notched all the way back in the heel down position anyway.
The plus side to the lowered frequency response is a very full sounding wah, with a very vocal midrange sweep. Probably more suited to single notes and overdriven tones than clean rhythm playing, but a good all-rounder overall.
The non true-bypass buffered switching isn't as big a deal as people seem to think. I have switched this pedal via a Keeley true bypass switcher, and compared this bypass to the built in buffered bypass. Whilst the buffered bypass does lead to a small loss of top end when in bypass mode, the affect really is very minimal and not really a problem.