Reading this thread at kboards reminded me of a pet peeve that I have and which many other readers share. It's the frustration with books that end on cliffhangers.
I hate them. If a review says that a book ends on a cliffhanger, then I won't download that book. I don't want to read half a story. I expect the whole thing--introduction, rising action, climax, falling action. I expect the main conflict to be resolved. I don't think this is too much to ask.
Twists, of course, are another matter entirely. I'll read a story that ends on a twist. I'll write one, too. (Buddy ends with a twist.) That's because a twist doesn't prevent the main conflict from being resolved. It's a little something extra, not a major something missing.
And that's the important difference. With a cliffhanger, an essential part of the story is missing. With a twist, all of the essential parts are there, and then you have this extra piece of misdirection on top of it. It's a bonus, assuming it's pulled off correctly.
Hugh Howey's Wool is an example of a great story that ends on a twist. It's not a cliffhanger, though, because the main conflict is resolved: Holston leaves the silo and learns the truth. A cliffhanger would have been if the story had ended right before the airlock's outer door opened. Whatever lay outside the silo would have remained a mystery. If Howey had done that, the story would have failed.
My advice to authors would be to avoid cliffhangers unless you make it clear that you're writing a serial. Even then, I'd avoid them. They're just not worth it. Foreshadow the sequel if you must, but give the story a satisfying conclusion. Your readers will appreciate it.