Thoughts on Water/Meth injection on a carburated motor for octane boost????

[pittpens24]

I have a 572 bbc dynoed at 742HP running 12.5:1 Comp. Also running a 850 QuickFuel carb. Was only thinking HP and numbers at the time of the build and now reality has set in. Realizing I can't run this on pump gas(91 is the highest we have), I was wondering who has run the water/meth set-ups and how well they actually work, pros and cons if any and also reliability of these systems. I know mixing race/airplane gas 50/50 is an option but not very practical when you are at a car show some miles away and the needle is in the red. Any info you guys could give would be greatly appreciated.