Aspect ratio > resolution
I'd strongly consider this, except that the 16x10 aspect ratio is too narrow to read tech PDF books on in portrait mode (my main use). An ipad mini is 4x3, which means I can read most cropped books in portrait mode on the 8" screen.
I don't care about the pixel density once it's above about 175 or so. Higher numbers tend to mean slower performance and lower battery life anyway.