I got this book largely to see what ideas from Algol survived in other languages. Especially since Tony Hoare once stated "Here is a language so far ahead of its time that it was not only an improvement on its predecessors but also on nearly all its successors." I also hoped to get a little programming advice from Dijkstra (there is some, but less than I'd hoped).
Overall, Algol is a reasonable language, with several quirks that I will now be aware of when reading older books. I used to find Algol's emphasis on typography amusing, but reading this book I realized that it served the same purpose that syntax highlighting does today. Especially since Algol had a rule that no whitespace was ever significant, even in the middle of reserved words (as in, "go to" and "goto" were equivalent, as would be "g o t o")!
What I hadn't expected, and the reason I rated this book so highly, was that unlike other programming language books Primer of Algol 60 Programming does not follow the general pattern of The C Programming Language, because, of course, this book pre-dates that one by nearly two decades. The pattern from K&R is timeless, and it's understandable that everybody follows it today, but seeing a different (successful) approach was something of a breath of fresh air. Individual language features are introduced in separate chapters with a somewhat informal commentary.
Funnily enough, the K&R approach included modeling the book after terse 1960s-era math textbooks. Primer of Algol 60 Programming was published in the early '60s by a trained mathematician.
Only one thing stands out from the text: early in the book, Dijkstra refers to a "girl computor." This is a reference to the fact that before digital computers, somebody with a lot of numbers to calculate would hire people to do the calculating. Often these were females. Today it would sound better to simply refer to a "human computor," but calling out the employee's gender wasn't so out of place in 1962. Additionally, I suspect that the distinction makes more sense in Dutch, and that the translator maintained the distinction even though it wasn't necessary in English.