I reckon that I read faster on an ereader.
Reasons?
Speed-reading coaches advise that you hold the page so that it is perpendicular to your eyes, so that the whole page is in focus to the same degree of sharpness. I can never hold any print book at 90 degrees comfortably for any amount of time: it ends up at 45 usually. Plus, the print changes its angle and often perceived lighting as it dips into the binding at the centre of the print book. I also find the lower contrast ratio considerably more comfortable, personally.
I tend to find that my eyes naturally move continually onwards with an ereader. This isn't always a positive attribute - I sometimes find my eyes reaching the end of the page before I've really taken in the last couple of sentences. With a print book, I'm much more aware that my eyes are skipping back and forth
(http://en.wikipedia.org/wiki/Eye_mov...nguage_reading makes for an interesting read). I feel that my manner of reading with an ebook is much more akin to another suggested technique for speed reading: that of following the text with a finger to force the eye to constantly progress through the text.
The final reason I think I read more slowly using a print book is that I continually get ever-so-slightly distracted by the physical book itself. I am unable to stop myself almost constantly being aware of my position per page; position as a proportion of the whole book read; where did I leave my bookmark? Oh dear, I'm drumming my fingers against the bundled pages on the right-hand side again.
In my experience, we don't fetishise the most useful technologies in our lives, but rather we become entirely oblivious to them. An ebook frees me to read the text, rather than a 'book'.