Just saw this, I give it a b to b- as a standalone film, c compared to the book.
The good points are that it is a decent gritty cop picture with a decent story that manages to keep you involved through the entire thing, although a bit slow at times. They managed to keep it about 90% close to the original book form. Also it shouldn't remind you too much of Taken, unless you have him already pinned as the Taken guy. He doesn't have any super magical fight scenes and the gun fights are very plain and semi realistic.
The bad -
Scudder is suppose to be a born and bred NYC street cop, yet he sounds like a fresh off the boat Irishman trying too hard to lose the accent.
The cinematography / scenery is off because of NYC gentrification, the original book was from gritty Dinkins era NY where there was real grit and grime to the areas mentioned in the plot line. The movie updates that to late 90's, but that still doesn't help it, the whole area now in the film looks like your standard lilly white rich Manahattan / rich hipster Brooklyn.
Much like the scenery, some of the actors in supporting roles just lack the panache of good character actors, where in a movie like say Taxi Driver, or Abel Ferrara's work you can look at the actors an go "yeah, I can totally see them in this role", you just don't get that in this film as much.
Slang. There is a central young black character in the film that has a few lines of slang written for him that just sound bad. Think 50 year old white guy trying to figure out what a 90's black kid would say. Awful.
Neeson plays a mentor to that character too, and while most of the scenes are benign and agreeable, one is absolutely ABC afterschool special level douchey, I'll let viewers pick it out.
Also they changed the ending from the book where it was very dark and grim, to standard Hollywood faire that is just alright.
