If I had to lodge an objection it would be with the coverage: all but six of the hundred bookplates are from the period 1875-1930, and almost all are English. Given the British Museum's extensive collections I'm sure there are some wonderful things from outside that narrow chronological and geographic range that might have made the cut. As Hopkinson notes, though, it's a small book and doesn't attempt comprehensiveness; given the limitations, he's chosen an impressive and varied selection.
Overall, a lovely book, highlighting some great bookplate designs and artists.