what i've found in testing both my K1 and K2 at the size 6 is the letters themselves are identical in size, however the default spacing between the letters is slightly wider on the K2 so the words take up slightly more length. the letters themselves are a bit smoother/refined on the K2 which may help make pictures look more refined but may make letters less crisp looking. the letters on the K1 have a course roughness to them which may look more crisp. My K2 screen has a slight yellowish tint while the K1 has a slight bluish tint which looks slightly more contrasty. giving the K2 screen the same bluer shifted color balance as the K1 would alone improve the K2 screen contrast. as for me i don't have problems reading either kindle so they both work fine for me.