Personally it appeals to me because my knowledge of filter theory and associated math absolutely sucks, so the three chapters on filters with plenty of detail, diagrams and (especially) code, along with formulas are a very welcome addition to my other books.
I'm not really that convinced by the authors rapid development app "RackAFX" yet, but i'll give it a chance in the context of the book. I can see the appeal from a teacher/author's point of view of abstracting the VST API, and building in an automatic/wysiwyg gui system in order to focus on the DSP, but I wonder if the extra boiler plate code might be confusing for beginners to plugin development. The app seems to be closed source so not good for future development. Also the GUIs it makes look like plugins did in the late 90s . I'm a bit biased because I think that IPlug has a really nice ultra-simple plugin abstraction/implementation, that is hard to beat for clarity. When I look at the source of a RackAFX generated plugin, there is quite a lot of boilerplate.
can you tell us a bit more now, what this mysterious Windows®-PlugIn and Socket® stuff is about?
It seems like the TOC on the focal press website is out of date. Socket® is now called RackAFX®. The chapter "Anatomy of a Plugin" explains what a dynamic library is (and a bit more) and then introduces the authors abstraction layer API.
i'm also interested in how detailed chapter 14 is (commerical Plugin APIs) is. i mean, does it cover VST and/or AU in decent detail? what about other formats like LADSPA, AAX, etc.?
On initial inspection the appendix A about VST2 and AU apis does not have much detail, particularly regarding AU. Other formats are mentioned in passing earlier in the text, but no detail about their implementation is given.