I agree. Ruth and (her husband? Forgot.) Butch are the best of the townies. I liked Ev Hillman's story and his grandsons' story, too.
I think this book would have been scarier without the sometimes cartoonish characters but maybe it was a necessary ingredient to allow for the zanier happenings in Haven. As King does in Needful Things, he delivers the scares with big laughs. In both books he satirizes the Maine denizens he knows and loves and pokes fun at them with more than a little glee. I like both novels better than when I first read them because it shows his range as a writer. Either way you slice it the laughs dull the axe blade of horror, but The Tommyknockers is closest to true horror. It gave me nightmares.
At the end it reminded me of old school alien encounter stories. You know the really cheesy stories that were a 30 minute episode of the Twilight Zone, or a 100 page, 25 cent book you'll find at the flea market. He took a simple premise and blew it up, it is very well written. I didn't get a scare, or a fright, more of a tingle in my spine of the creeps. Some of the parts gave me a chuckle, and others I had to put down to laugh without losing my place. I haven't yet come to Needful things, so I cannot comment. Yet.