I don't think I can tell you whether it works or not. My reaction to RPF ("Real (living) People (slash-) Fic") is a restrained no-thank-you. This is literally Real People Fic, and I have the same reaction even though the plot element doesn't involve sex. Only I can't back away because it's in the middle of a fantasy series that I'm invested in. Now that I think -- it's the horror format, making me read something I don't want to read, except my reaction isn't squick or gross -- it's this other discomfort.
Since I can't pass judgement on that part of the story, I'll skip around it. Here's the rest: Jack the Ripper is back, only now he's killing rich white guys. Our favorite squad of unwillingly-magic-sensitive broken coppers are on the case. They are forced to entangle further with London's magical underground, and this is both traumatic and fruitful.
At the same time, everyone has personal issues. (I did say "broken".) Costain and Ross are on the trail of a particularly juicy artifact -- separately, and later together. They need to trust each other and they are, basically, utterly incapable of it; it's the most screwed-up relationship I've cheered for in a while. It would make great TV.
Crap, if this were TV, they could get Neil Gaiman for it. Dammit. Now I have to want this.
Quill just wants to do his job, which is impossible. Lofthouse still knows something she isn't telling the team. Sefton... Sefton isn't completely screwed this novel, now that I look at it. This worries me. It's that kind of novel.
There's a lot here, even aside from Neil Gaiman. There's the Ripper, and an evil Rupert Murdoch-alike -- I mean, eviller than the real one -- and a London going slowly batshit with class riots, and parallel invisible tensions in the magical world. (The gentrification of London Below, you might say.) It's all part of the plot but I'm not sure it all gets the attention it deserves. On the other hand the author gets credit for avoiding bloat. I think it's a win but not an unmixed win.
Showing us more about magic is always a tricky path for the author. We get reasonably good navigation here. In the first book, magic was overwhelming and mad. Here we start to see rules. Some of what we see is still overwhelming; other parts become more clear and systematic. But then some of the system is horrible in its own way. (Magic is very much about sacrifice.) And we start to see the underlying series arc, which is... clearly a crime. Someone -- the Smiling Man -- has committed a crime against London. The motive, means, and opportunity are still completely obscure. Not to mention the question of how you stop the perp and bring him in. I guess we'll find out.
(Postscript: Only save the gibes about the "game designer's pixellated imagination", please. We're all in the same business here.)