I used to have a bias against large books.
I remember ordering
Journey To The West from a used book store one year. I saw the acts on PBS and wanted to read the stories. Well, that thing was four volumes, easily 600-700 pages a piece. I remember remarking to the owner of the store, "Wow, that's a lot of reading." And they said, "That's what makes it so great!" I honestly had never thought of large books that way before. (I was wizened at the age of 25.)
For a long, long time, I was always cognizant of the length of everything -- of the chapters, of the book, of any arcs within the book -- and I always felt a little frustrated when I was in a large book (500+ pages) because there was more stuff I wanted to read. Even today, I will think about the length a little bit each time I pick up a book, but I rarely decide I don't want a book because it's large.
Today, I think I honestly like books of all sizes. The change has come become I can become lost in most books. At that point, the page numbers don't matter anymore.