This question is a proxy for "which is better, Comma.ai or Tesla?" or which one I'll prefer to get.
If you're reading a book you're obviously not driving?
What I mean is, what company will let me (safely, see next FAQ item) read a book while sitting in the driver's seat of a private car, being the sole human in charge of the car.
Technically you can do this in a Yugo?
It has to be safe to do! Hacking the self-driving tech to bypass the "is the driver watching the road" mechanism also doesn't count.
So also legal, though if the law were to fall blatantly behind what's clearly safe, we can talk about that.