I mentioned on another thread about how I found his novels tend to be incomplete, with endings that seem more open-ended than all issues rounded completed.
Yet his characters are fairly engaging - even if they do tend to be early middle-age Bob Dylan & soft rock fans.
How does Stephen King compare as a writer in general? What would you say are his strengths, and which are his weaknesses?
It depends on which books as his career spans quite the time period now. Early books like Carrie and Salem's Lot are good reads, but exactly as you state: Good characters, improvised plot and endings.
We all have to remember that Stephen King is fanatical about NOT OUTLINING stories. His exact quote is: An outline is a bad fiction writer's last resort.
I don't adhere to this statement. Was Tolkien a bad fiction writer? Someone say yeah, I dare you. Anyway, King doesn't believe in outlines. He lets the story come out onto the page and then does a heavy re-draft to attempt to weed out the inconsistencies and errors. Early in his career, this made the books less than stellar. They are still quite entertaining because, despite his self depricating statements, he has an insane amount of talent at holding the reader's attention.
Now that he has written most of his life and done a lot of good stories in the process (and good drugs), King has even stated himself... he takes more time. He still does 2000 words a day, but instead of doing those 2000 words from 7 to 9:30 or 10 in the morning, it takes him until late afternoon, nearly supper sometimes. This is good for us. Those 2000 words are better.
The quality of his books steadily goes up and culminates with great reads like Cell, The Dark Tower V, VI, and VII, Bag of Bones, and even On Writing is very good whether or not you're interesting in being a writer (I am, coincidentally). He still doesn't outline, or even do a lot of notes I understand. But his mind seems to grasp whole pictures better. Cell is amazing. Wolves of the Calla is great. The Dark Tower (Book VI) made me cry four times (I counted).
Plus, he loves Harry Potter. That gives him ten points for Gryffindor right there.