I bought a copy of this when it first came out (the huge version).

I think of it as an "ideas" book -- especially regarding situations or landscapes I'm totally unfamiliar with (such as when travelling). It gives me a starting point.

My nephews like browsing through it because it's very visual.

It also gets the creative, improvising part of the brain going. So it's perhaps useful in inspiring positive thinking and positive action in a sticky situation. But then, so is any decent survival book.

Generally, I don't take any survival manual as "the whole truth." But when I browse three or five regarding a given topic, I have some idea of the right questions to ask.