Erm - I'd argue that some of his examples of "ketogenic" are rather higher carbs than many require to be Ketogenic. I typically eat about 75g - 90g a day and I'm a long way from ketogenic.
I can't argue with his commentary on being ketogenic and the effects on the brain at low glucose levels. It corresponds with what I and others have observed.
I suppose if one trains for a triathlon ...he is more likely to reach ketosis with 75g carbs/day...he is fairly detailed with his data collection...lots of useful information for those who are exploring.