I don't think this is exactly what you're asking about, but I use my iPad mini for a large majority of the reading that I do. I don't use any fancy reading apps; however, I find that the small size of the tablet is perfect for reading because it fits nicely in my hand and its incredibly portable without being intrusive. The big plus to e-readers, at least as far as I've found, is the incredibly expansive library of (illegally downloadable) reading options ranging all the way from scientific papers to high fantasy novels (although I mostly stick to philosophy essays and math proofs cause I lack imagination). All in all I'd say that my iPad certainly fills a niche that regular books or my computer can't, and it's become a pretty integral tool in my technology arsenal!