I haven't been on this board much, but I noticed that the Haiku chain features mostly 5-7-5 poems. Of course (especially in this age) I am not dogmatic about how they should be written. But I was under the impression that 5-7-5 is not typically how haiku is written in English -- particularly when it comes to professional contests. Reason being is that Japanese haiku is not divided by syllables, but by more stringent "sounds." (eg To-kyo is 2 syllables, but 4 sounds).
Anyway, I know it is just for fun, but I was curious if anyone has thoughts or has adhered to different styles (2-3-2 for "stressed" syllables or iambs or 3-5-3 for syllables or just short long short with ~10-12 syllables). I think the shorter -- more Japanese style -- Haiku makes for a more difficult challenge.