I really enjoyed Ben's book. The only reason it didn't get 5 stars it's that it has to be perfect to get that rating, and it isn't quite so... but if I could have given it a 4.9 I would have done.
Peter Grant is a very engaging if slightly hapless hero. He has 'greatness thrust upon him' - he doesn't plan on becoming a ghost spotting, magic spell casting copper, but kinda falls into it. But he's fun to be around. It makes a change to read about a policeman who isn't sitting from the usual policeman tropes - alcohol, dysfunctional personal relationships, that sort of thing.
The other major plus in the book is the characterisation of London itself, both on the everyday descriptions of places and life in the capital, but also in the way the book weaves in the magical world into the fabric of the city. As if, were you to look sort of sideways you'd be able to see that would just out of view. The magic doesn't feel 'stuck on', it seamlessly weaves info the real world.
As a police procedural it's more than half decent as well - there's a case to be solved and Peter and the rest of the Met, albeit some of them in a disgruntled way - too much magic going on - step up to get to the bottom of it. There's a good twist of two - not the sort that take your breath away, but enough to keep you guessing, and they turn out to be 'neat', both in the sense of cleverly realised, but also in explaining stuff.
Downsides: some of the characters are a bit two dimensional, the narrator's voice, whilst charming most of the time, gets a bit much at some points, dare I say it, a bit annoying, and there's a bit of inconsistency in the styling. The set piece at the Opera House takes a little while to get going, and slightly chunks along to start off with. This made me think he couldn't write action very well, but once the riot for going it really came to life.
I'm deffo, going to read more. I think it will develop and get richer in the series. At least that's what I'm hoping. It's a great start and great fun.