About hydrae, the most irritating thing I find about them from a townie perspective (when making cases) is that there tends to be a 'dominant head' that changes every post (e.g using the Kiro/Kips thing, their first post might sound like Kips, the second like Kiro, etc.), so often it feels as if you are interacting with two different people under one persona which only needs to post once every 24 hours. Compounding this is the fact that different heads think up of different points, so if one person were to take issue with one of these points, the head not responsible of it would merely say something like 'wait for the other guy to respond', and it might take a long time for that other head to respond since sharing the work of playing was the point of making up the hydra in the first place. Since most people here consider the inconsistency of other players' views as scumtells, and since inconsistency is innate in every hydrae except for mentor-student ones, I think hydras go against he spirit of the game in this respect, just as lurkers do with their lack of information and posts.
I don't have qualms about the supposed increases in skill level though, since there isn't a skill cap in the game, and I do agree with what Serp said, but yeah, I don't really support hydras either.