My own independent, peer-non-reviewed, published study:
On a "real" hardcover book, it takes longer to moisten an index finger, reach up and access only one page - turn the page - and use the other hand to properly place the turned page --- than it takes a Kobo to refresh a page. And only my wife - in my study - has mastered the "one-handed page turn on a hardcover book" maneuver, whereas, of course, Kobos require only one hand to turn a page.
And in the same study, I found that the occurrence of "paper cuts" was almost eliminated by the use of a Kobo versus hardcover books. (There was one guy who received a paper cut while reading the "Kobo Quick Start" brochure.)
Long live Kobo.