I'm reading it slowly (it was a Christmas present) but it has been fascinating. It deals with lots of areas I know little about, like the interiors of trains, lighting arrangements etc. which are amazingly interesting, but which I had not thought I would care about.
That's a coincidence... there was a man across from me on my easyJet flight from Amsterdam on Thursday reading this. He opened it up the second he got on and read it for the whole, admittedly short, flight. I made a mental note to find out if it was any good and I'll definitely seek it out now.