"the best way to enjoy it is to rip out the final chapter and imagine your own conclusion."
I found his novels to be a bit hit and miss, and I've not read any of the Dark Tower series, which I hear is quite good, possibly because he doesn't have to end the story arcs as quickly.
He does write quite excellent short stories, which for me is the test of a good writer. Any idiot can put a story across in 100k words, but doing it in 10-15k requires real skill. Plus there is less need/desire to write a complete ending.