Well I like the fact he spends a lot of space on the lineage of the different engines, especially the direct & indirect influences from abroad.
The first half of the book is a set of topical chapters that is somewhat repetitive as it reviews the same historical developments more than once. He spends time providing a lot of institutional details that gets confusing fast.
The second half of the book reports on the engines themselves, and there tables of specifications in the appendix. I've not taken a close look at the engine specs yet, but there are better experts than I in these forums that can comment on the accuracy of what reports.
-Blogs