You are right that there is no evidence of "terrible" damage produced by sleep deprivation (except for horrifying truck accident statistics, airtime disasters, etc.).

However, if you ask anyone who tried free running sleep for more than a month about the cost of sleep deprivation, you are likely to hear a very definite private research conclusion: "Never back to the days wasted by lost or irregular sleep".

The contrast between good sleep life and bad sleep life is so dramatic that you will find no one who hesitates about the difference once it is exposed in practice. As adrenaline and cortisol are good masks for sleep deprivation, the above is particularly true in creative professions with mild to severe adrenaline deficit.

What do you think,can the free running sleep be the good option?