When I love a book, it can't be too long. I used to go to the bookstore and look for series based on how fat each book was, or at least how many books in the series there were. A big part of reading for me is reading to escape. I want to go get lost somewhere else for a long time. As long as the writer can deliver joy for me, I don't care how long it takes to get to the end. Like you said, don't pad it, but, if it's good, it's good. I get what I call "book hangovers" from the really amazing ones. Sometimes, it's so bad you have to start it over again. I'm pretty sure I'm not remotely alone in that. Doesn't mean a short story or a novella can't do that, but typically, the longer I am immersed in something, the more time it has to seep into my very bones and really begin to consume me, making me dream about it and stuff. That's the sweet spot of reading for me.