[Quoth]

Obviously even 7" 300 dpi ereaders are better than the ghastly 9.7" Kindle DX and DXG which is maybe 167 dpi. Similarly the 5" Sony PRS-350 or Kobo Mini may be more pleasant than the older 6" Kindle Basic models (and other old 6" eink) for ebooks at the same size text, though they have the same number of dots, because 167 dpi is too low. That's why laptops/Monitors use subpixel addressing and specially designed fonts as most are only 90 to 140 dpi. Fortunately for Latin-Roman fonts as in Western languages the horizontal resolution is more important so on a 120 dpi LCD screen you have a sort of 360 x 120 dpi resolution for text. It means the horizontal edges are blue or red, but our colour eyesight is much lower resolution than mono. Also CRT or LCD on computer usually has 254 levels of grey rather than 14 on eink, so anti-aliased diagonals are better. The best colour eink is only about 4000 shades/hues/levels compared to about 65,000 for 16 bit LCD or gfx cards or about 16,000,000 for 24 bit "True Color" (not actually true colour).