That would be http://lesswrong.com/lw/5n0/optimizing_sleep/44zu
As before, I’ll suggest testing yourself against Gbrainy and dual n-back (as well as Anki, I suppose). I recently recovered my old polyphasic sleep logs off a backup CD I didn’t know I had, and unsurprisingly, my Gbrainy scores were consistently bad; not that I ever felt I ‘adapted’, anyway.
On a side note, I just finished up a few months of on-and-off melatonin use, recording nights with my Zeo. I haven’t updated my site yet, but the summary is: total sleep did fall by ~1 hour, REM fell by ~25 minutes, fewer awakenings, and morning feel was the same. So, I can definitely recommend Zeo for tracking things to do with sleep.
My melatonin results are now up: http://www.gwern.net/Zeo#melatonin-analysis