[DNSB]

Generic e-ink assumes the screen is 590x775 while the default profile assumes 1200x1600. On most newer HD e-Ink devices, a 590x775 image is noticeably softer than a larger image. My personal preference is tablet with no limitations on image size so a large map is zoomable though I think that the default profile doesn't shrink images in newer calibre versions.

Edit: should have read Kovid's message before replying...