I agree with you that the response of this speaker (or any speaker) is much more than the location of the drivers.
As an aside, I don't plan on building a speaker (though I may build a power suppy and/or amplifier), but I wanted more information as to speaker design (part of my engineering mind -- I always want to find out how things work). That book is very detailed but incredibly dense and really not for beginners. For instance, the very first chapter is a chapter on "how speakers work". Is there a description of how there are typically multiple drivers in a single cabinet and how a crossover is used to direct certain frequency ranges to certain drivers? No. Instead, there is an indepth discussion of how a driver itself works, including a ton of diagrams, curves, etc., for the various parameters of a driver and how a driver might be selected. One tidbit I've gained is that stuffing affects the Q and f3 of a speaker. That's both for amount (i.e., volume) and type of stuffing.
Anyway, I don't mean to hijack a thread about Joe's speakers, since he has been waiting for these a long time and is now happy -- and should be, at least judging by the photos.