That's interesting, I'm the opposite to you. I much prefer to reading books using an e-ink screen.
I have a Kobo Clara HD e-ink reader. It has a 300 PPI screen which is very comfortable to read from. I can read for long periods without getting fatigued. I can't do that using IPS colour monitors or tablets, even the high-resolution screens. With an e-ink screen I can read properly, not skim-read like I do on a monitor or tablet.
My thoughts on whether an e-ink reader is suitable or not:
- Small e-ink screens (e.g. 6 inch) are only suitable for paperback-sized, text-only books (fiction or non-fiction)
- Small e-ink screens are not suitable for reading PDFs
- A general rule of thumb when deciding whether to purchase an e-book: If the physical book is larger than a paperback size, then it is unlikely to be suitable for an e-ink screen (unless the book is text-only).
- Small e-ink readers are not suitable for any books with complex layouts, layouts designed for larger books, or books with colour graphics: charts, diagrams, photos, etc. Amazon, in particular, encourage publishers to convert as many books as possible to Kindle format regardless of whether those books are suitable for e-ink screens.