Considering the time period in which it was written (this was published in 1980, which means most of his thesis work was probably done in the late 70s, and Saikal even states in the introduction he wrote much of the book before the Shah was even removed from power), it's a very interesting take on what contemporaries thought of Iran as a power (or really, lack thereof). Of course, it turned into a shitshow, but that all happened after publication.
Most of his analysis came in the last ten pages or so, so if I hadn't read it, most of the book would have just struck me as a history of the Shah's reign. Informative, but not much in the way of analysis (again, until the very end).