I've really loved some of Jonathan Coe's books (The Rotters' Club, House of Sleep) and not liked some others (Dwarves of Death). This one sits somewhere in the middle, to my surprise. It takes a long time to get started, and I found the mundane details of the main character's life dull - well, they are supposed to be, but couldn't we have established that rather more quickly? It's more interesting when he gets to Belgium, and by the end I was emotionally engaged with him, his wife, his situation.
By the end I was sorry it was over - the impact of finishing with a present-day epilogue in which many of the main characters are dead is poignant. On the other hand, I didn't like the MI5 characters' double act - it reminded me too much of Ealing comedies, and felt like it was played for laughs according to a formula.
I note that 1958 was the year of my own birth, so the main characters are contemporaries of my parents. I don't know whether Coe is over-doing it, but London in 1958 seems really depressing, as if the war and rationing have only just finished.