I had one of the original blue Superchargers as an alternative to lugging around my SLO back in the day. It was a cool little (I should say big) pedal that had a huge amount of gain on tap. Slapping this sucker in front of non-master volume amp (a plexi was my favorite) turned it into an instant fire breather.
The noise issues that a lot of people complained about with the originals were due to the placement of power transformer housed inside the pedal. It looks like Mike has addressed those issues by going with an external PT. The noise wasn't actually all that bad on my pedal, but I actually had James Peters tweak mine and he got it quieted down about as much as you could expect from a high gain tube pedal. Fun fact - James Peters is high gain in a small package.
Honestly anybody expecting the GTO to be an SLO in a box (a large box at that) is going to be disappointed. I was more impressed with the actual pedal construction with its billet aluminum sides than its tone. It was really built nicely, but it couldn't hold a candle to my Hot Chili Tubester. That thing had just as much gain on tap, was dead silent and had this magic tone imparting quality about it that made any amp that you stuck in front of sound instantly better. My GTO is long gone (sold it about 2 years ago), but I still have the Tubester, which is weird since I don't own any tube amps anymore.