The other day I had a brief Twitter conversation with Memory from In The Forest of Stories about whether one’s enjoyment of a particular book is related to the amount of time it takes to read it. It doesn’t seem like something that should make a difference, yet for me, how long it takes to reach the last page is actually a big factor in how much I’ll like a book. Perhaps it is simply because books that do not engage me take more time to read. I keep putting them down and then picking them up, then putting them down, sometimes to never pick them up again. It doesn’t really matter whether the book is long or short. I remember times when I spent days reading a tiny 150-page novel and two days whizzing through a 650-page doorstop.
Books of diverse length. From top to bottom: read (enjoyed), read (enjoyed somewhat), read (loved), did not read. There, now my dirty secret is out. I have never read The Stand.
Here’s an infographic on how long it takes to read 64 popular books. It uses 300 words per minute as the measure, and doesn’t really take into account complexity of narrative structure, for example (i.e. something like the Lexile measure). I am probably on the higher end of reading speed (though absolutely not as far as Larry Nolen at OF Blog of the Fallen), and that might be another reason why I don’t like to spend a lot of time reading one book. Maybe it’s specifically a fast reader problem.
You might ask: ‘ok, you can read pretty fast, but do you retain anything?’ Personally, I do have a really bad memory for books. But it doesn’t seem to matter whether I spend just a few hours with a book or a few days trying to read it ‘closely’. In fact, I think my bad memory is another reason I read books quickly. If I spend too much time with one book, that means there is a day or two when I don’t touch it, and those couple of days are just enough for me to forget what happened in previous ten chapters.
And now, if you’ll excuse me, I have to get back to Dan Jones’s Wars of the Roses before all those dukes and earls get mixed up in my head and my enjoyment of it takes a dive.
Genre-bending 
Your idea of “much” reading and most other peoples’ is way different.
IMO, the reverse is true. If you like a book, it doesn’t matter how long it takes. If you’re not enjoying it, it takes forever.
It took me more than 40 years to realize I did not have to finish a book I started if it was becoming a chore. It doesn’t matter how long a book is if it’s engaging. In fact, if I am absorbed in it I am sorry to have it end. I think of being able to read fast as more of a curse than a blessing, because books I love are over too soon .
I think I derive more satisfaction not from good book lasting longer, but from rereading. I blame it on bad book memory.
And yes, I am now much better about abandoning books. Maybe being a bookseller has made me into a highly promiscuous reader.
For me, my time with a book depends on the type of story. If I love it and it’s very prosy, I will take longer so that I can relish in the word-smithing. If I love it and it’s action packed or a thriller, I’ll read it more quickly.
If I’m not into a book or totally hate it, it will take me forever, having to go back over paragraphs and pages because I’m not comprehending it or my mind is wandering.
I’m bad at putting books down, but I’ve gotten better. I abandoned one book this year so far, The Stepsister Scheme, which was my SF book club selection. Reading it was making my mind explode with boredom and frustration. I also had a ton of trouble with E. Bear’s New Amsterdam, but forced my way through it, since it filled slots on 5 of my challenges on WWEnd.
Before I started blogging (by which I really mean having ARCs show up at my door), I felt that a book was a good fit for me if it was long enough that it took me at least a week to read. It was cost effective, and at the time I didn’t live as close to a library. These days I prefer shorter books, because I don’t function nearly as well as I used to without sleep, and I have a bad habit of not being able to put the book down until I’ve finished it.
I’ve always lived within a reasonable distance of a library, and out house had enormous quantities of books, so maybe the sheer number of volumes overwhelms my brain. It’s even worse now that I work at the bookstore.
Especially with all the cool author talks at P&P!