Hi. I don't know anything about the Monte Allums mods, but I have a couple of Keeley modded MT-2s. They are awesome! Check out the soundbites on the Keeley website, I think Monte has soundbites on his site too. The Keeley mod adds a lot of volume and distortion to the pedal, yet there is still clarity to single notes at high gain that I cannot find in other pedals. The controls seem to have more range in the Keeley mods as well. I have played through many distortions and fuzzes, but ever since I got the MT-2 modded by Keeley, I keep going back to it. I must point out though that I use a solid state amp, and I am not sure how the high amount of gain and distortion may react with tube amps.
I think there was previous discussions on these 2 different mods on another thread, so try a search on that as well. Hope that helps...