Well, I knew it would be difficult reading. After all, the book is a collection of scientific essays on the dinosaurs-birds connection, essays created by and destined to scientists, not educated laymen. But I was totally unprepared for the extreme difficulty of some passages, particularly those concerning anatomical issues. It would be an optimistic assessment, if I said that I understood about 25% of them. On the other hand, in the essays of the book's second half, concerning dinosaur ecology theories and how they correlate with present-day bird behavior, things got a little smoother, but never really smooth.
Nevertheless, the subject is of tremendous interest for history of life amateurs and professionals alike, so even the comparatively little information I could understand in the "anatomy" section - seconded by the excellent illustrations - was very enlightening. The article covering the feathers and structure of "Archaeopteryx" was of a particular interest, since this is the very fossil which began the whole story of the dinosaurs-birds relationship, and it apparently has still a lot to say today, over a hundred years after its discovery. Also, the article covering the "beginnings of flight" theories, from the energy conservation point of view, was a fair summary of all relevant conflicting views, and so of great usefulness in clarifying this quite thorny issue.
Overall, if other amateurs are bold enough to tackle the book's heavy scientific jargon, they are in for a very rough but very interesting ride.