I have one of the first versions with the internal switches coming in. I wanted to try one out for awhile because of the Bush thing, but also because Reverand Gibbons has done cool things with it. I hear the low end can be a bit weak, but I think running it through my Showman with a 15 cab should help that out. Hope it all works when it gets here.
I have the internal and external switch version, both are great and really flexible pedals. It does tend to get a little high on the treble, so I keep the tone below 11 o'clock.
honestly i think they sound pretty similar, some TGP people claim there are differences but i didn't find any myself. I had the original, then a reissue with the switches popped up for a killer deal, and i bought it because it was so convenient.