Ok, I know alot has been said on how impedance does and doesnt affect percieved output, but this questions a little different....I think...
Does output scale linearly with impedance? i.e. with all else equal (which it never is but lets pretend for a second) does doubling impedance double how hard you drive youre amp? If not how does it scale? Is there a maximum impedance, after which theres just no point increasing it further as itll make no difference? IS there a minimum? can you get distortion out of, say, 2k? (and will it be 1/10th the output of 20k on an otherwise identicle pickup?)
What else changes with impedance, from ridulously low to high? What would a 1k PU sound like compared to the same pickup as 4k? (well, it wont be the same PU, but you know what I mean!).
I cant help but think that this shows how much I dont know, but hey, gotta learn somehow :).