@ Nimis, robmandu
I agree that it might not be certain, that serifs will make a larger text more readable; especially when taking the medium (the screen) into consideration, which indeed doesn’t inherit the same qualities/characteristics of the written paper.
I happened to stumble back in here after receiving some lurve and I have to say that the idea of using some kind of visual cue for comments exceeding certain character count thresholds, is, if only a little, interesting…
Let’s say, one idea might be to color grade each paragraph, sentence, or words; the longer it gets.
Maybe it’s too elaborate to consider for Fluther, which of course, is already in a perfected state ;) but as an artistic idea, of visualizing information, why not. Guess I might try my hands at making a test plugin for Wordpress to see how it looks like.