Lenovo has announced that a variant of the Yoga Book running Chrome OS is in the works and should be available mid-2017.
http://www.notebookcheck.net/Lenovo-announces-upcoming-Chrome-OS-variant-of-popular-Yoga-Book.187962.0.html
Excellent example of marketing fluff :(
While the Windows 10 version has greater application compatibility, it also runs more slowly and has weaker integration of the unique HALO keyboard and Create Pad than its Android counterpart.
Which is Lenovo fault only. I have also doubts about competence of their software development department because Yoga Book Windows software updates were shipped with amateurish batch scripts that can never work.
In addition to the speed, security, and simplicity Chrome OS
That's really bad joke, Chome OS and security does not match at all. The real reason is that such junk systems does not have any regular security updates so Lenovo no longer needs to bother to fix anything. The system is always left vulnerable.
The Windows 10 variant sells for US$449 due to the added cost of a Windows 10 license, but running Chrome OS means that this added cost would be cut out.
The cost of Windows 10 license for big OEMs like Lenovo is around $10 and don't forget that Windows 8.1 with Bing edition was for free.