It's difficult to be objective when you know (and like) some of the authors. Fortunately it's not a problem in this case since I don't have anything bad to say about their work anyway so I don't need to be diplomatic!
Of course it could be argued that anything I say here might not be totally impartial but I leave it to you, the reader, to make that decision – I just wanted to be open and clear from the start.
“Clear” is definitely a word I'd use when describing the book. With a subject like this, which isn't exactly what you would call bedtime reading, any confusion would make the book unreadable. Maybe this is helped in my case by the fact that I've been using PowerCLI and PowerShell for quite a while now although I certainly wouldn't put myself anywhere near being in the same league as the authors.
Having some exposure to PowerShell I think is probably a pre-requisite for this book. Or at least you should have a willingness to learn a bit about the language first as the book drops you into some fairly sizable scripts right from the start (assuming you go from cover to cover that is). Thank fully these scripts can be obtained from the publisher's website – the days of typing in programs from a magazine are long gone!
One of the things that I like most about the book is that many of the day-to-day Virtual Infrastructure tasks that most people do repetitively through the GUI have been converted into PowerCLI scripts. Not all of them will be immediately useful to everyone but they give you the flexibility to change how you work whilst at the same time being fairly easy to follow. Having the way that PowerCLI works with the vCenter API explained (with examples) at various stages should give any reader the confidence to strike out on their own. Just remember to test any modifications on a non-production system!
My only criticism of the book is one that is general to books of this type. Inevitably, by the time that they are written, edited and published the technology is on the cusp of moving on and it is possible for such books to become outdated quite quickly. In my opinion, PowerCLI is here to stay. PowerShell is certainly gaining lots of traction in the IT industry and so as a foundation for scripting VMware vSphere this book should be a good read for some time to come, even if a little tweaking is necessary in the future to make the documented scripts work with the latest versions of PowerCLI.
The only other thing (and this is a note for the publishers / amazon and the reason that it only gets four stars) is that it would be great they offered a bundle of the print book and an electronic version (e.g. Kindle) for a reasonable price. I know a fair few people like me who would like that sort of combination. Actually, offering an electronic version at all would be good – I gather from Jonathan Medd's interview on the #vsoup podcast that there were formatting issues with the script samples that the publisher is working on.
Otherwise an excellent book!