I find the history of the Great Central to be very interesting, so I really enjoyed this book. It contains photos of various locations during operation or construction, and then photos taken in the late 80s/early 90s showing what remains (or what doesn't). It's very meticulously done and highly informative.
Would easily have been four stars, but I've made it three because the author regurgitates the "continental loading gauge" myth not only once, but twice, in the first few pages. It's been comprehensively debunked many times - the GC was built to prevailing British standards current at the time. Repeatedly stating in various books that it was built to "Berne gauge", which didn't exist until 15 years after it was built anyway, has given the GC a status and reputation it didn't deserve.
Besides that, it's a good read, but it's an error that really irritates me every time I come across it - which is sadly very often.