Not the best history book I've ever read, but good enough to probably be my new default for anyone asking for a recommendation on something that covers Alexander the Great. The key hook feature Mr. Worthington adds to differentiate his take here is looking at both Alexander's AND his father, Philip II's, reigns, as flip sides of the same coin. I buy his argument that you can't really consider Alexander at all without having a solid grounding in what his father did first to set the table.
Proceeding from that, we get a decently-written, reasonably quick history of both reigns, with a focus on comparing the two to each other. The author's bias seems to lie with Philip II, favoring that ruler's propensity to enhance his kingdom vs. Alexander's propensity to enhance himself. Worthington makes a reasonably effective argument that Philip II was a better ruler due to the amount of time and effort he put in to making sure that his conquests were well-governed and integrated into his kingdom in a way that was designed to be lasting.
The book is most enjoyable in the Philip sections, for me, mostly because that's just a much-less-covered period of history. Alexander is basically history's first celebrity, and we have more primary source material on him than on anyone else until the Romans start getting weird. So, to anyone who's even dabbled in ancient history, his story is well-known, right down to the various disputes over what actually occurred at certain points in his life, but even those disputes and their various possible answers are well-known at this point.
Philip? Not so much; there's much less hard source data to work with, but Worthington does an admirable job of pulling together to story of his life and reign in fairly thorough details, noting properly when big gaps exist in the sourcing.
All in all, the book is an effective overview of the reigns of these two deeply-intertwined rulers, with an added bit of comparison that is more weighted towards the author's point of view than the straight history, but serves as a solid analysis of the differences between the two, whether or not you agree with the conclusion drawn. Follow this book with Dividing the Spoils and you'll have about as good of a layman's understanding of the entire Hellenistic Era as one would probably need.