Anyone at all interested in the serif / sans serif debate should take a look at
this article. I have been through courses on design and was feed the old "serif for print, san serif for screen" philosophy. For many years I admit to being rather snobbish in my adherence to the code. The article linked above successfully revealed my unfair bias. Still, I was surprised to discover that I had been reading on my KT for several days with a san serif font selected (Segoe UI) without any apparent annoyance or decrease in readability. I hadn't even noticed!
I still prefer serif fonts for print (and eReaders), but at least now I know why: personal preference.