This isn't a bad novel, and I don't think it "drags" as some would have it--there is enough motive force behind the novel (action, plot development) to keep you there, BUT

The main character just isn't particularly interesting and the novel fails to flesh out its alternative history in a way that would make it truly intersting. We get a smattering of the catastrophist/gradualist controversy (derived from SJ Gould is my guess), and Victorian social attitudes and mores get depicted (but not discussed) pretty well.

However, we don't get very much on the difference engines or how the technology interacts with Victorian society or on why Byron would have made a successful prime minister in these circumstances or . . .

Well, we could go on at length as to topics the two novelists might have turned their attention to.

But at the end of the day, not a bad way to spend a few days away from more serious reading.