Unashamedly biased, this paean to engineers is written in much the same vein as popular science books are. In other words, it's light on detail and it focuses to a far greater degree than is strictly accurate on a few individuals, painting them as heroes battling against an enemy. This makes it good light reading. It tells a few short stories, and tells them well, aiming to give an overview of the purported renaissance of engineering. Unfortunately I don't think it does a particularly good job of telling what engineering is really like these days, seeming to concentrate primarily on a few small project teams and juxtaposing them with The Other of nasty large foreign concerns. But real engineering throughout the world - especially the best of it - consists mostly of small teams and small companies, the giants that we've all heard of such as Tata, Shell, and Boeing being very much the exception to the general rule.
Aside from that there are two other glaring errors, both in the chapter which waxes lyrical about the justifiably famous early video game "Elite". Throughout the rest of the book Spufford does a very good job of explaining technical concepts in ways that are accessible to a well-educated layman. Unfortunately he fails, in my opinion, in explaining some of the concepts necessary here.
Furthermore, this is the one place in the book where he makes a prediction, and he gets it wrong. In lamenting the passing of the "bedroom coder" in the video games industry, and opining that the future belongs to large studios, he missed one of the biggest events in recent video game history, namely the advent of the iPhone, which has many excellent video games developed by individuals or by very small companies. Some of them even work in their bedrooms. The fast pace of hardware innovation, the rapid development cycle of pure software products with no pesky manufacturing, and the low cost of software development means that software engineering is almost uniquely suited among engineering disciplines to individual endeavour.
But even with those errors, it's a damned fine read. Recommended.
There are at least two editions of this book: the shorter one originall published in the early 60s, with significant cuts imposed by the publishers, and a much longer one published by Heinlein's widow after his death. I read the latter.
Because it's Heinlein, there's politics here: just as with The Moon Is A Harsh Mistress and Starship troopers there's emphasis on personal responsibility; and like in The Moon Is A Harsh Mistress, there's lots on freedom from interference by the state and sexual freedom with lots of polygamy. Heinlein clearly doesn't trust politicians, saying in this book that they're all primarily interested in power over their fellow man for its own sake, as opposed to using their positions and power for good. He is, perhaps, somewhat naïve in saying that one politician in particular can be trusted with money because he's only interested in power - because money is a great tool for getting, maintaining, and abusing power. It's no coincidence that modern politicos get more generous with their budgets as elections approach!
The book also has a lot to say about religion. It's not entirely negative, treating it as being a useful tool for some to "achieve enlightenment" but not a necessary tool. It certainly doesn't have much good to say about our contemporary religions.
Finally, as a stylistic note, the vast bulk of the story is presented as dialogues between characters, including that which I sometimes slate other books for - expository dialogue. Here though, I didn't even notice that that's what was going on, thus proving that in the hands of a competent writer, this method can work just fine.