I have watched a crap ton of these kinds of shows and really like Nordic-Scandinavian noir procedurals because they tend to be more myopic, character driven, and tightly written-which this is. If you want overly dramatized twists so you can't guess the killer and wild plot beats with gorgeous, likable, actors for the partners, which 90% of these shows are, this is not for you.
This is for fans of the also pretty great Canadian show Cardinal, Midnight Sun, Mare of Easttown, Wisting. Personal, slow burn but well written shows. Not something as bombastic and shocking like Happy Valleys plot beats develop into or The Killing, The Bridge, Pagan Peak, with substantial sub plots. This is 8 episodes a season, much more tight.
The characters are flawed and realistic and the casting is subversive of type. Though, the leaders I would say are still quite attractive, the hotshot young one has a great character arc across the 3 seasons, and the relationship between the detective and him fits the show very well. The lead is only unlikable only if you don't like competent, confident and over 30. I don't need or want characters to be likable. I want them to be understandable and compelling in ways I haven't yet seen much of, or at all.
The writing is excellent. I always know who does the murder regardless of the plotting, it's just the way it is unless the show deliberately withholds information from the viewer. Instead, the red herrings and the investigation proceeds in such a way as to bring a very nice character arc and thematic crescendo, which is much preferable to me over a wild twist. Every character and every piece of dialogue is there for a purpose, even if you don't realize it until the last couple episodes, and even side characters are well written. They're dynamic, sometimes for descent queer rep, sometimes to hit a trope or to subvert it.
The acting delivers, though isn't academy award level, but far more serviceable than anything you'd be watching on mainstream. Very pleasantly surprised.