These books are well written and comprehensive. Most of the explanations are clear, reasonably concise, and fairly complete, and the books teach a great deal by prose, example, and practice. They are, by far, the best resources I have used yet.
But they still suffer from what I call "Microsoft blindness", the ingrained assumption that the reader (a) has worked extensively in the Microsoft space and (b) has never worked anywhere else. There's a Microsoft Mindset that the writers assume the readers have, and if you happen to be experienced in non-Microsoft technologies, it's almost like reading in a foreign language. If you speak the language well but not fluently, you can translate it, but you struggle to "think" in Microsoft -- or, at least, I do, having long non-Microsoft experience before entering the Microsoft world.
These books could be improved substantially if the writers kept in mind that some readers come from other environments, even if they just did it in sidebars with a signpost here and there, for the things that are quite reasonably obvious to Microsoft devotees that aren't obvious at all to those coming from the outside. One example of many is ongoing references to the .Net development framework. If you haven't developed code for Windows, which is quite possible for an incoming system administrator, many of the .Net references will make little sense, while to a .Net developer they are obvious and intrinsic to the environment.
Microsoft has simultaneously gotten better about playing well with other technologies while making their own more and more comprehensive. Their authors and editors should keep that in mind for future editions.