Wow, you guys do read a LOT. Having a short attention span, I just can't get into fiction novels anymore. I used to read Star Trek novels as a teen, but those days are long gone. Although I have the entire collection of Harry Potter books, I've only read Prisoner of Azkaban. Even nowadays I can't seem to sit still and read for more than an hour unless I happen to be reading one of my graphic novels or some articles in a magazine.
Even if you read really slowly an hour is long enough to get an average fiction chapter in...why not read fiction in chunks in the same way as nonfiction? I often do that because I usually read several books at a time. Or what about short stories? I love short stories, and there are a few collections I'd highly recommend: A Good Scent from a Strange Mountain
by Robert Ollen Butler, Stories of Your Life
by Ted Chiang, and my favorite book ever, Einstein's Dreams
by Alan Lightman. The stories in Einstein's dreams run from 2 to 6 pages in length, I'm sure even your short attention span could handle that!
As for the "dense" non-fiction books I have (mythology, religion, history, etc.), I read them in segments, or I refer to them if I want to look something up (but with the Internet at my disposal, it's much easier to look things up on my cell phone or tablet).
I do have three e-books I downloaded from the Android Store and from Amazon; namely, Cosmic Coupling, Edgar Allan Poe: Complete Tales and Poems, and The Complete Tales of the Brothers Grimm. I read them mostly on the mobile devices.
I love the big ebook collections! I reread all of the Sherlock Holmes stories and novels, plus a couple other Conan Doyle novels with one of those collections. I also have the complete Dickens, though I doubt I'll read it all; Great Expectations
is one of my favorite books, but A Tale of Two Cities
bored me to tears.