Many people liked old Stanley Kubrick's movie The Shining, being a huge fan of Stephen King's books I hated it. It twisted the story too much for my taste, but overall a classic of all times.
Doctor Sleep took many parts Kubrick's movie changed from the books and set them right trying to fill the plot holes the first movie left. The best part was the ending that felt so nostalgic for the people who have read the original King's The Shining.
I advice to read both books The Shining and Doctor Sleep to enjoy this movie to the fullest. I totally enjoyed it and I'm looking forward to another adaptation of King's books like this one.