Early in "Welcome to OZ 2.0", Vincent Versace says that if editing an image will bring it 2% closer to your original vision, then you have to edit. That's a good rule to keep in mind as you read the techniques for using Photoshop that this book provides. (Note that there are substantial differences and updates in this edition so that fans of the earlier volume will probably find something helpful to them by exploring the updated work.)
The author believes that the artistic photographer leads the viewer through a photograph, and does this by a combination of global and selective adjustments to the original image in tone, lighting and color, among other things. The book consists of four tutorials that each take a single image and follow it step by step through the series of Photoshop activities that Versace uses to process a photograph. The reader is expected to follow along in Photoshop with the images, which can be downloaded from a special website, that also provides other useful materials (including a couple of free and demo Photoshop plug-ins that will be used in the tutorials). The author is not so much interested in making a duplicate of reality (if that's even possible in photography) as in creating an artistic print. The four images include a portrait, a glamour shot, a leaf shot and a flower shot and one has to admit that the final results are quite lovely.
Having been taken to task in the past for saying that a Photoshop book was for advanced users, I will say that this book went beyond any Photoshop techniques that I currently use. For example, like many photographers, I currently adjust my white balance by looking at an image and adjusting the temperature and tint sliders to my satisfaction using Lightroom or Adobe Camera Raw. Versace uses a far more elaborate system for making what he calls sensor corrections by selecting individual light and dark points and making individual curve adjustments for each color channel, although he then makes further color adjustments to suit his vision. Verace uses dozens of Photoshop layers and masks to develop an image to his satisfaction.
Whether such an elaborate procedure moves an image more than 2% closer to his or her vision is something the individual photographer will have to decide. For me, I thought that I would be unlikely to use most of the author's procedures. On the other hand, I might have occasional use for some of the procedures, such as adjusting the tonality of an area through the use of layer masks and painting on the masks in shades of grey, to, for example, decrease apparent depth of field. Moreover the overall theory of adjusting tonality and color to lead the viewer through the photograph was of great applicability. Versace's use of filters that I had never even considered, like the lighting effects filter, will surely prove useful to some photographers.
To get the most from the author's techniques, it is almost mandatory that you download the images and follow along, step by step. For me at least, that was a time consuming procedure, and made me wonder, during individual steps, if the process was worth what I learned. And yet, even though I don't expect to use many of his techniques, the effort seemed at first worthwhile, not just to acquire a few new tricks, but also to gain a greater understanding of what was going on in Photoshop. I must confess that eventually I found the process of following the author's adjustments too tedious, and given the fact that the effort seemed to exceed my calculation of the 2% rule, I quit about two-thirds of the way through the book. Nevertheless, if you find this kind of detailed processing useful to you, you may benefit from completion.
If you haven't developed fluency with Photoshop, this book may be over your head. On the other hand, individuals interested in squeezing the last drop from the post-processing process should investigate this book. For myself, I have been happy with the level of techniques provided in another book by the same publisher. In "Vision & Voice: Refining Your Vision in Adobe Photoshop Lightroom (Voices That Matter)", David DuChemin covers the same ground in a less intensive fashion.