For reference materials, textbooks, comics, and other image heavy and laid out precisely books, I almost exclusively prefer PDFs and only read them on my tablet.
If it's a book with almost zero images, like most fiction, how they're laid out doesn't matter, and I enjoy the ability to read anywhere on any device. I've never found the need for an e reader and regularly switch between my tablet or phone. Reading comics on the phone isn't for me, but there are a lot of people that don't mind it.
For reference materials, textbooks, comics, and other image heavy and laid out precisely books, I almost exclusively prefer PDFs and only read them on my tablet.
If it's a book with almost zero images, like most fiction, how they're laid out doesn't matter, and I enjoy the ability to read anywhere on any device. I've never found the need for an e reader and regularly switch between my tablet or phone. Reading comics on the phone isn't for me, but there are a lot of people that don't mind it.