I learnt much new about the rigid 8-wheel stock, including about their later re-builds, and about the later "Jubilee" 4-wheeled stock which hadn't really come to my notice before.
Only concern was a quick look at some of the tables of coach re-numberings, where there was the occasional inconsitency between the dates of conversion to electric stock for the particular carriages I was interested in (i.e. the bogie stock we're currently overhauling at the Bluebell Railway), and an unfortunate mis-credit to the late "Robin" Greenaway, who was known as Robert/Bob when I met him.
But a very clearly laid out book, easy to dip into and find the information you're interested in, all nicely presented, and also very readable. You can balance the fact that it's softback against the reasonable price, when compared to other similar specialist railway books.