@hacdias Personally, I prefer paper books to e-books. Granted, I don't have an e-reader, so I read e-books on my phone or computer. I guess that long books might be better with an e-book, since I wouldn't look at the spine and think of how small a dent I've made in the page count.
About your "to-read stack", I just read a nice article about long reading lists. It's called Treat your to-read pile like a river, not a bucket.