I don't have a whole lot of experience with drive pedals, but I do have a couple. I have an Xotic AC Booster and have been unable to get any usable, good sounds out of the RA with it. It sounds nice with other amps, but I've resigned to sticking with the amp's overdrive and I'm happy with that. I do have an Xotic EP Booster that I keep at the end of the FX loop and it sounds amazing, use it for solos.
I also have a Suhr Rufus fuzz pedal and I'm still trying to figure that beast out. It seems to sound terrible on the clean channel. It sounds nice on top of the RA's gain channels, but it is entirely dependent on where it's at in the pedal chain. I haven't put it into live service yet - still experimenting with it.