Ditto. I tried the near OD strategy for an Auckland-Rome series of flights. It turns out that you reach the point where they dont work anymore - at least not easily. At 4x the recommended dose I couldn't sleep that last 6 hours. I seem to max out at about 20ish hours of sleep. I almost got a DVT - swollen leg and very painful. I just avoid flights now.

Edit: premature post.