Unfortunately, I know almost nothing about the Sony ereaders, but they're supposed to be really good (check out februraryfour's comment for ideas about specific ones). And e-ink technology is getting a lot more subtle as the refresh rate goes down. BUT STILL I LOVE MY NOOK COLOR THE BEST OF EVERYTHING.

The big things to look for IMHO from an ease of use perspective is ease of sideloading and pageturning speed. See if you can play around with any perspective devices before you buy them :)