Yes, those are the sacred texts. I do believe the O'reilly book is worth paying money for. It's extremely well written, and I think it's painstakingly crafted pictures of memory layouts and thorough coverage of lifetimes and traits are tremendously helpful.
Thank you. Well, now I have to choose whether I prefer the physical copy or the Safari subscription... :D
For me, the ebook version on my laptop in Calibre has been great; no regrets buying that, instead of the dead tree version.
It's a nice complement to the open-source Rust book too, which may as well be read in digital form.