Today I delve a bit into the subject of meta-moderation, or how I do it. Generally I find it kinda neat to play the "Great Judge" and how I do it.
1) Blatant abuse of moderator power = unfair mod, period. Don't care whether or not I agree with you, if post is provoking a flamewar and you mod insightful, you're getting hit unfair.
2) Wrong positive mods I have a tendency to leave alone, you said insightful, I called it informative, generally I'll leave it blank.
3) Correct positive ones are fair, correct negative ones are fair
4) I often try to meta-moderate the "tight" posts as well. If I'm not sure I'll dig into a posts history and meta-mod how I feel. Worst case scenario I'll leave alone. I've been known to dig into an off-topic moderated post, up the chain and decide that it was still in the chain of logic and zap it as unfair. I do respect a certain chain of conversation in a meta-moderation, however if we deviated from C++ to Peanut Butter sandwiches in the first post, you're offtopic and if moderated as such I'll uphold. However at the fifth or sixth level of a thread I tend to care not about the offtopic mod and won't tolerate an offtopic mod, often marking them unfair.
5) Generally I find myself not using the "unfunny" mod, granted my sense of humor might differ from yours. Unless it's a blatant troll or flamebait of course.
Anyways those are my ramblings for the evening, enjoy!