I think they are all fine as long as you can mostly stay stock and just add switches for the diodes, a 4th knob if it has the Ruetz thing, and so on. I have been using the GGG Rat board, but I need to switch. It is just a tad too wide for the smallest MXR sized boxes, and they changed the output buffer biasing so that it is more sophisticated than just running at unity gain. ...So because of the GG change to the output buffer thing, you may actually want to go with the Slow Loris, or the Tonepad s/b fine, too. I think I built one of the Tonepad ones some time ago.