I finally got around to actually see the movie during Easter, and I had a blast. I don't want to oversell it or anything, but basically it's a pretty good thriller.
The focus on actual investigation was a welcome focus. This is a major aspect of the comics that often get sorta glossed over in movies.
I couldn't help myself thinking about the worldbuilding they did in this movie. For example, it's made very clear that this is a version of Batman that is early in his career, stated to be in his second year of crimefighting, which brings me to the comics:
This movie is 100% inspired by the limited series "The Long Halloween", which has a loosely similar plot. The Long Halloween also inspired Nolan's Batman movies, so it's pretty influential.
Something the movie and tLH share is that they sorta show Batman slowly transitioning from fighting regular street crime and conventional organized crime, to fighting his rogues gallery of costumed weirdos. I won't go into too much detail, but it's a neat detail, and frankly I've always loved seeing Batman battle actual, non-costumed criminals like the mafia and such, or indeed serial killers and the like. Out of all the costumed superheroes out there, he is one of the more well-suited for it.
So yeah. It's a good 'un.