A while back people here were all talking up e-books and I was curious to see what it was all about but couldn't see myself buying a reader. Then one day it occurred to me I could try it out on my phone (smartphone, runs Android, has 3.7" screen, 480 x 800 pixels). Originally I just wanted to see if it would work, and wasn't expecting much because of the not-book-sized screen. But it turned out really well and I read with it every day now. No issues with eye strain or page size. (Moon+ Reader Pro, 18pt serif font, 5-8 words a line, 17 lines a "page", a yellowish wallpaper that looks like a paperback page... the books themselves are mobi-to-epub conversions produced by Calibre, the original mobis coming from torrent libraries.)
Using the phone is a tad awkward sometimes if I can't rest it on my knee, but otherwise I have no problems (except when people call...).
I take it Kindles are more like paperback size and reproduce the appearance of a "book" page more?