Ok since we're on the topic...
I've always used crystals my IPAs and pale ales. I picked up 10 lbs of light Munich. I want to try and sub out the crystals. I don't mind crystals but I want to expand the horizons. What percentage of Munich would be ideal? 10%? I don't want a whole lot of malt taste. Basically for body and color. Thought about trying Maris Otter for 1/3 to 1/2 the bill too.
That depends on what you're looking for. Also, depends on your IBUs as to whether or not you'll taste it. I have found that when using unfamiliar malts I will do the nano-mash experiment at different percentages and try to imagine what that'd taste like with hops. The experiment is outlined a couple of issues of Zymurgy ago.