E-ink physically moves pigment particles with every update, so it refreshes a fraction as fast as an LCD — but for page turns that is barely a limitation, and for everything else you adjust.
For manga and comics you want an 8-inch color panel like Kaleido 3; for PDF pages, size beats color — and both needs pull you toward the same mid-size readers.
Six inches disappears into a pocket, seven is the modern default for novels, and ten-plus exists for PDFs and writing — the right size depends on what you actually read.
A used e-reader can be a bargain if you check four things before paying: battery health, screen condition, account deregistration, and the fine print of the platform's own rules.
Kobo pairs a polished store and tight library integration with tighter format rules; PocketBook trades polish for format freedom — the right pick depends on where your books come from.
E-reader front lights shine sideways across the screen instead of at your eyes, and the warm setting adds amber LEDs — understanding both changes how you judge every spec sheet.