I read a bit on the polyphastic sleep society's website [1], and it looks entirely premised on the idea that light sleep is 'non recovering', yet it makes up >= 65% of our 8 hour sleep schedules, so they cut it out via schedules that drop you directly into deep sleep (REM and 'slow wave sleep').

I would like to know more about their claim of the unimportance of light sleep. I also don't like that the people cited in the article are writing books and pushing product.

[1] http://www.polyphasicsociety.com/polyphasic-sleep/beginners/