I haven't played on GT-6B, I have played on a GT-10B though. I am kind of so-so about it, some really good effects, some blah. Kind of like Boss pedals, there are a few jewels, a lot that can get the job done, and some stuff that I Hate. I don't honestly know how the pitch shifting is in the GT-6B, I would imagine pretty good though because Boss has some pretty good pitch shifting pedals.
