Neurological studies notwithstanding, there are significant logistical differences across the means-of-presentation. I find it more work to review a book in e-format, since all the logistical parts of the process–flagging passages, taking notes, flipping back to check a reference–take longer. Even with a decently-featured reader application, it’s just not as quick and convenient as working with paper. Some of those issues apply to personal/recreational reading as well–for example, checking the endnotes or index on non-fiction.
I’ve been a fan of audio books for a long time, though mostly for situations where reading is not possible–driving long distances especially. And there I’ve found readers who made the experience better–the late Patrick Tull and David Case were particularly lucid presenters of Patrick O’Brian’s Aubrey-Maturin books, and Case did a really nice job on the Flashman novels. But at home or in a plane, I much prefer eyeball reading. (And a mediocre performer will put me right off a book.)