We should keep in mind that the moderators aren't necessarily here to be experts on the topic, but rather to determine what is and is not within the scope of the site, what constitutes spam or abuse, etc. That's not to say that we should promote someone with zero knowledge of bitcoin, you need to know a fair amount just to understand the scope at all, but much like hiring an IT manager we need a blend of management ability AND technical skill.
To that end, I'd take a known trusted member of the bitcoin community with no previous StackExchange experience over someone with a 5-digit StackOverflow score any day. A high score might tell us they know the system, but it's much easier to teach a good mod how to work the system than to teach a good programmer how to be a mod.
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