Took me a while, I admit (even though they were chapters I've skimmed through quickly). First important point about this book: it's really **in depth**. Well, author is not decompiling Powershell on his own :), but he covers some topics I've never seen covered in any other PowerShell book.
For instance: * details of remoting * good description of how credentials work in PS * CIM (it's not that different from WMI, but it's still good to learn the diffs) * DSC (brief description, but unlike to some other books - it covers & emphasizes some very valid points) * Workflows (ok, I think they are useless ;P but now I have a better basis to claim that)
Neither time, nor money wasted. Why 4 & not 5 stars then? Some code samples were very easy-going, debugging chapter has disappointed me a lot, chapters like GUI/DB one doesn't make much sense TBH (it's about using .NET classes, so why bother?). Anyway - if you want to refresh your Powershell-fu, this book is quite a good choice.
Sometimes one has to get into the mind of an enemy, and this one helps an unlucky admin accomplish that. More seriously, if you have to work with PowerShell (and there can be worse fates), this will help you slog through weird variable definitions, cryptic error messages and garbled syntax--and you will even have some fun along the way. Plus, you can occupy yourself reading this while your PowerShell scripts execute with all the alacrity of a lethargic snail.