When someone tells me that they don't like King's work, I often ask which books they've read. To me, that's like saying you don't like the Beatles. From which era? Which style or genre? With both iconic artists, there is simply too much variety for such blanket statements.
It is true that many of King's works - though not all - contain some dark element. He has brought us homicidal cars, vengeful prom-goers, vampires, and alcoholic fathers who attempt to murder their family members. He has also brought us post-apocalyptic heroes, characters with the power to ease the pain of others, real female heroes, and some of the most touching tales of friendship found in print. His textbook, On Writing, is one of the best books I've read on the craft of writing. Ultimately, he captures who we are, for better or worse, and brings our hopes, joys, and fears to life through the written word. I understand that some don't want to examine the darker side of humanity, and anyone in that group should steer clear of Mr. Mercedes. (Note the clever car pun.)
In this mystery/suspense novel, retired detective Bill Hodges rouses from his depressed, suicidal state when the "Mercedes Killer" taunts him with a letter. This letter, intended to psychologically torture the retired cop, has the unintended effect of giving Hodges a renewed sense of purpose and sending him on an investigative journey. Since I refuse to spoil the plot any further (you've got Wikipedia for that), I'll just say that the pay-off is there at the end. I was ultimately glad I stuck with these characters through this wild ride, despite the sometimes gruff language and disturbing details. I've seen enough true crime shows to understand that serial killers don't get to be the way they are in happy family homes, and the fact that King provides a basis for why his killer acts the way he does just reinforces my earlier observation about King's ability to write real characters. There are some cheesy phrases and "Kingisms" along the way - mostly little jabs at pop culture, but again - these are timely and generally ring true to the character thinking or speaking the lines. I only rolled my eyes a couple of times.
If you can stand a little darkness, if you like journeying with characters through a cat-and-mouse high-stakes game, and you want to read this before it becomes a mini-series, then sit back and enjoy the ride with Mr. Mercedes.