...well stated.....Maybe I'm a little biased because I'm a musician and primarily a guitarist ("That **** all starts in E"- so apt!), but I did like the book. Always enjoy the Dark Tower and general SK mythos references.
When I started it wasn't terribly familiar with King's more recent works and at first I thought the novel was very derivative of elements of his older, more classic works, especially "It" and "Pet Semetary". Like everyone else, I guess, I also anticipated the ending would be that Jacobs' ultimate goal was to revive his dead family. But the more I think about the story the best comparison to anything else is actually the horror film "Phantasm".
Anyway, the ending: while I appreciate that some people can consider it ludicrous, as a big Lovecraft fan I think I sort of "get" what King was going for. That's not to say that Lovecraft fans can't also consider the ending ludicrous! Just that I personally didn't take issue with it and even enjoyed how literal and alien the description was. This isn't heaven or hell (although we can all agree it's closer to hell?). No, this is an entirely alien, incomprehensible afterlife. It's not much different than the majority of Lovecraft stories. The world is not supposed to make sense to a human, that's the point.
To wrap up I wouldn't say I loved it but I enjoyed it and found to actually be a page-turner of sorts.