To be sure, I could know more. But I think you're being dismissive by characterizing this as superficial.
If I buy a book on SPDY (or any technology), it is likely because I want to use it in a production/live environment.
I want to buy a book on technology from someone who has run a live system, and got the battle scars one gets from doing so; who has learnt from the experiences, which they can then share.
When it comes to technology, one can research all they like about it, but until you have practical _experience_ in a live environment, I would call it 'superficial'.
(From the blog post it is not clear; if you have run all these technologies live then I agree, your understanding is not superficial)
I think that depends on who the audience is. If you're a CTO at a company that's up and running and live and you're beginning a deployment of something new, then yes, you need an overview rooted in hands-on experience. But if you're a guy who just wants to learn something new because "I might use this in the future" or "I'm just evaluating this" or whatever, a book which is based only on theory/research can be wildly useful if it helps you shortcut the learning curve to learning the tech. Actually, if it helps you shorten your own learning curve, it's beneficial in either of those scenarios, in a sense.