[JohnDae]

By specifications (Carta vs Pearl), any modern non-capacitive-touch non-frontlit device should have better screen than those older devices. But I guess in practise manufacturers might coat newer devices with blurry plastic if for no other reason but to put them on par with their frontlit devices. Or E-ink might supply lower quality Carta screens for 167 an 212 PPI than older premium 167 Pearl screens.

I guess I would need to buy one of those older premium Kindles and some modern Carta device, both non-frontlit and non-capacitive-touch, and compare to what I have. Or find someone here who has seen all of these devices to give a comment on the comparative lack-of-display-coating / ink-on-paper likeness?

I do prefer 300 PPI, it really added a lot of crispness over 212 PPI to images, pdfs and serif text. But for reading just text with the right font 167 would be fine.