Just read this over, many major topics of the book aren't addressed here such as improved memory & brain function, improved reaction time, reduction of Alzheimer's(by sleep flushing the brain of certain toxins consistently linked to Alz), importance of sleep cycle timing(deep REM sleep vs lighter REM sleep, etc), and possible links to Autism.
I also noticed a response to a question on memory from the article's author saying something like "well I didn't look into the impacts on memory so I can't comment on that". Also, this reads as a hit piece in general involving significantly less research and details involved, so I'd take it with a grain of salt.