As I read History of the Future more, it's becoming more clear that it's a somewhat unbalanced view into the events pertaining to the recent VR beginnings. And that's both fair and expected, as you simply can't cram all the details needed into a book of this scope. But it is something to note. 

For instance, while Brant Lewis' internal e-mail at Oculus when the Vive was announced seemed to imply Oculus was far behind the competition, the reality is that they were actually still on a pretty good path, actually perhaps doing better than HTC was internally in some ways. Anyone who isn't aware of the details (which I won't describe but may if someone is curious) may thus not be aware, and take his message at face value, truly believing that Oculus was far behind. Instead, from my perspective, knowing what I do, Lewis' message sounds like he was more leveraging HTC's reveal in a dramatic way in order to motivate others at Oculus to push themselves further and do better.

Another missing detail, or perhaps something that was not focused on so far up to about 3/4ths of the book as far as I can tell, is that it was not made clear how instrumental Gear VR and mobile was to Carmack being convinced to join Oculus, and it didn't go into his interactions with Samsung either. This can have several effects on the reader IMO. First if someone doesn't know how he interacted with Samsung and what happened there, one might believe that Carmack was less justified to argue for mobile, when, at the time, it was certainly very logical, and in hindsight perhaps still just as logical and important to the company. 

And there are more and more examples I could point towards. Like an obvious one is just the limited info about what was happening at other companies other than Oculus. Still, the book is a fun read and provides many details not seen anywhere else.