I highly recommend this book to all people with an interest in learning F#. The examples are very good and go deep. Most books just scratch the surface and focus too much on syntax, this one shows practical applications. I wouldn't recommend it to be the first thing to read for an absolute F# novice, though, I would start with some introductory tutorial blogs or articles first.
This is the third book I read on F# and while all of the previous ones were good, this one shines!
The authors assume no prior knowledge of functional programming, but this is not a book that will only get you started with F#; it will literally make you an expert, as the title suggests. This is no surprise, since Don Syme is one of the authors.
This is an interim review and I expect to upgrade the rating later on, when I have read further - which I will certainly be doing as the overall approach and style are greatly to my liking and this promises to prove at least among the best offerings available.
However, I want to flag a potentially crucial difficulty: Chapter 2 presents a "first" program which is refreshingly more demanding than the traditional 'Hello World (!)' offering ... that program, unfortunately, does not run as presented (at least not on my primary system). I tried two approaches to putting things right, neither of which has borne fruit, before deciding to move on. The difficulty apparently has something to do with how (or how verbosely) a function that is part of the String library needs to be specified. Now, actually, the description of the program and its working are sufficiently clear that seeing it all happen on screen before me is, arguably, not crucial. And, eventually, I expect to come to understand how to put things right (I am mainly a Mac user and not well up in Visual Studio, nor do I need to be in order to use F#).
So my gripe is this. Any language like F# can be expected to evolve (indeed, my FSI reports version 3.1, which is conceivably part of the reason) but this book is in its third iteration and should take care to keep up, especially with the psychologically critical first program. I look forward to being able to read the appropriate erratum/update on the book's APress website.