I may be busy for the next several hours 
Initial impressions:
Brian Karli said that the book exceeded his expectations, and that his expectations were high. I feel the same way. The book is remarkable.
Imagine the dual language anniversary edition of Erwin König's "Die Bücker Flugzeugbau" but with about twice the content. Like the König book, Fascination Bücker divides most pages into two columns. One German, the other in English. The translation (at least my impression of the English) is near perfect, the voice being that of a modern textbook.
Also like König, the authors have divided the book into sections detailing each model of Bücker, but the sections are larger, more detailed and feature many high resolution pictures. In this type of book one often comes across the same old pictures seen elsewhere but this is definitely not the case in "Fascination." Of the several hundred pictures in the book, I recognized only a handful of historical pictures that I had seen elsewhere.
There are a number of areas in which "Fascination" goes far beyond previous books on the subject. I learned many facts about Carl Bücker's life and history, and about the early days of Bücker production that were new to me, (for example, the Luftwaffe initially refused to consider Bücker aircraft because they considered them to have been financed with foreign money) I also very much enjoyed the sections that describe the ways that Bückers are operated and revered today. "The Bücker Scene" chapter is very well done.
As you read through the book you will find mention of many friends and acquaintances, and it is wonderful to see these people recognized for their contribution to to our lives and interest. I particularly enjoyed seeing Joe Krybus, Frank Price, Mike Meloche, Mira Slovak and "The Forge at Teufen" (Albert Zeller et al) covered so sympathetically.
160 of the 500 pages form the appendices. Exhaustive lists of competition results, manufacturing records, aircraft serial numbers, a glossary of terms and more are provided. A remarkably thorough list.
Although I have compared the book to those that came before it, it is much more than simply an expansion of those. The production quality is extremely high, the pictures are fascinating, the text is informative and interesting, and the technical details exhaustive.
I found a couple of minor typographical errors, but they are trivial. I suppose that writing a book is something like making an oil painting; at some point you have to decide when it is done! I think that Klaus-Jochen & Christoph stopped at the right time. As Charlie Miller has suggested, "Fascination Bücker" is an example of what happens when someone decides to go beyond what is merely acceptable, and to make something that is simply the very best that they can do.
The authors ask that we continue to contribute pictures and information so that their library can continue to expand. Perhaps there will be a second edition one day. Should that happen, it would be good to see even more about how Bücker aircraft came into the modern world. Jesus Ballester, Marcus Bates, Charlie Miller and Jose Martin for example, all deserve recognition. An index would also be a welcome addition.
Thank you Klaus-Jochen & Christoph. Fans of these wonderful aircraft will be for ever in your debt.
If you haven't ordered a copy yet - what are you thinking? Get that credit card out right now and surf over to http://www.meinfachverlag.de/Shop/index.php?id_lang=1