Another major benefit I could have mentioned is that you learn better reading a physical book as compared to an eBook (http://www.businessinsider.com/you-remember-books-better-tha...). Again, a lot of that has to do with multi-sensory input.
http://digitalcommons.brockport.edu/cgi/viewcontent.cgi?arti...
http://go.galegroup.com/ps/anonymous?id=GALE%7CA289721760&si...
http://search.proquest.com/openview/f98bc7b7d8194ba66b948d94...
(Found after a quick Google Scholar search, there's probably a lot more material out there.)
Although I still think eReaders are more limited than physical books as far as sensory input is concerned, it appears that the difference is small enough not to make a serious dent on learning.