All my failures that weren't my fault were due to pump seals leaking sometime or another... however SMC seems to have addressed this issue with new style pumps and my current kit has not failed due to a pump issue in a long while. I will say that Steve @ SMC has taken the upmost care of me exchanging out my failed kits with brand new ones without asking any questions... usually ships out the same day received.
I will also say I've experienced quite a few scary failures that were caused by the vac line used for the meth controller MAP sensor popping off during hard runs... I have my boost gauge line T'd with the meth vac line so I know if my boost gauge doesn't read... my meth's not shooting. I also pay attention to my wideband more than I do the road.
I can not express enough the dangers that a methanol tune... especially an aggressive one if you do not know what you're getting yourself into. One may think and wish its as simple as installing the kit, pulling fuel, adding boost / timing, and smiling... but if you don't religiously monitor the methanol system's and your engine's operations, you could be in for a bad day.
Whenever I look into another methanol kit for whatever application, I'll remember to contact you folks at CoolingMist... I may use a custom-type application in the future.