The debate continues.
Since at least the 1980s researchers in many different fields—including psychology, computer engineering, and library and information science—have investigated such questions in more than one hundred published studies. The matter is by no means settled. Before 1992 most studies concluded that people read slower, less accurately and less comprehensively on screens than on paper. Studies published since the early 1990s, however, have produced more inconsistent results: a slight majority has confirmed earlier conclusions, but almost as many have found few significant differences in reading speed or comprehension between paper and screens.
I have now more or less switched to ebooks. The convenience factor of carrying all your books is too good pass up. Moreover, I have noticed that I read more. However, I do find that every now and then I want to go back to my paper books and I always notice the difference. Reading from a paper is far far better.
But then I come across a word I do not know and I try and invoke the dictionary on the paper book which then takes me back to my ebook.
The only hope is that the ebook screen becomes better. In the meantime, the debate continues!