Unless you plan on putting the G major 2 in front of your amp then the wah will be going through your amps fx loop signal and that usually is a recipe for not so good sounding wah tones. I also used to have TC G system, which uses the same wah block as the G major, with the 4 cable method and even with the wah block placed before the amp i still didnt think it was all that good. Here's one of the demo vids for the G major 2 and he does use some wah in it but without knowing exactly what his signal chain is, its hard to gauge how it would sound otherwise.