What I find engaging about the show is the atmosphere and the history. I'm not one to watch CSI-style shows (the show is often jokingly referred to as CSI: Whitechapel), but I think it's interesting to see the theoretical origins of forensic analysis and to witness the beginnings of medical examiners finding their way as detectives. Yes, it's fictionalized, but much of it is plausible.
On the other hand, I find two out of the three principal male characters somewhat off-putting.
Edmund Reid (Matthew Macfadyen) expresses feelings of guilt about how he failed his wife by giving her false hope about their dead daughter, but then proceeds to be unfaithful with a new lady friend each season. I like the actor fine, but I'm not crazy about the hypocrisy of his character. Homer Jackson is the roguish American who, while gifted in the "deadroom" (the morgue), is, not to put too fine a point on it, a ne'er do well and something of a slimeball. Indeed, the only recurring male lead I like is Bennet Drake, played by Jerome Flynn in a BAFTA-nominated performance.
While I recognize that the show's depiction of women is probably about as good as it gets for the time, historical accuracy isn't always pleasant to watch. With rare exceptions, women are treated as objects and property in Ripper Street, and are frequently abused. Even Jane Cobden, an elected representative of the community, gets no respect -- after actively pursuing her, Reid breaks up with her when the vengeful newspaper editor runs news of their affair on the front page. It will tarnish both of their careers (hers more than his), but he is so consumed by the case on which he's working that he gives not a whit. She's reading the headline as he enters her office, and he's all, "Yeah, but about this case I'm working on -- I need your help with that," completely dismissing her legitimate concerns about their respective reputations, and later sending her a "Dear Jane" letter at a hint that his job might be threatened by the scandal. Reid is cowardly in other respects as well: it's pointed out near the end of the second season that he's long permitted Drake to do his dirty work for him.
It's a little like Mad Men: I can appreciate that the show is written and acted well, but that doesn't mean I find its content entertaining. I see enough misogyny in real life: I don't need to see it in authentically-realized detail on my television screen.
Amazon has purchased a third season of the show, but it's unlikely that I'll stay with it. I'm not sorry that I watched it, but there are just too many other programs vying for my attention right now.
Side note #1: I found it interesting that at least five actors from Game of Thrones have made appearances on the show (the aforementioned Jerome Flynn, Iain Glen, Joseph Mawle, Kristian Nairn, and Paul Kaye). I don't know if the sets are near one another or what, but it's been kind of fun spotting them. :) Mawle reminds me a bit of Daniel Day-Lewis as Bill The Butcher in his role as Inspector Jebediah Shine.
Side note #2: I'll grant that the show is educational: I'd never heard of phossy jaw until I watched the third episode of the second season, "Become Man." I rather wondered if the special effects team was paying homage to Sandman's Mazikeen with their depiction of the symptoms. Their visual appeared much more extreme than the sketches and period photographs of the admittedly horrible and deadly disease.