An electronic device requires turning it on and (for the most part) sitting to read, perhaps being distracted by a blip on the screen, and the hassle of turning from one page to another electronically if you're trying to 'digest' something.
You're also subliminally prepared to turn it off after reading whereas a book can just fall to the floor
50% of the time with a physical book, your eyes flit to the lower left rather than scroll a page up and/or down (another physical activity)
I prefer a book
Most eBook devices do not scroll up and down. They are set up to exactly mimic how a book works. AND you can read one handed and easily turn the page with your thumb.
eBooks are going to take over the market in the very near future and the basic reason is it literally costs nothing to produce an ebook wherein it is very expensive to create a physical book out of dead trees.
I love my physical books and have en extensive collection of very expensive first edition (not to be confused with first printings) leather bound and signed by the author scifi novels. The have gilt edging, archival quality paper, silk bookmarks sewn-in and certificates of authenticity that validate the author's signature AND show which numbered copy I own of a limited printing and most now are worth 100 bucks or more. AND everyone of them are also on my Kindle cloud because I do most of my reading on the go (in the car, at the doctor's office, outside in my emergency mobile zombiepocalypse garden, etc.)
Physical books will soon be like drive-in movie theaters. There will still be some around but they will be a novelty OR a high-end luxury item like the ones I described above. Not because one is better than the other but because eBooks can be created with a few mouse clicks after they are written and edited. Used to be it took months even years to get a book in print AFTER it was written and edited. Now its takes literally seconds. That alone changes the publishing paradigm add in the fact anyone can upload their book to Amazon or iTunes bookstore etc. without begging some publishing company to do it for them and get paid for doing so and anyone can see Dead Tree Media is gonna take it's place next to 8-track tapes and Sony Betamax movie tapes.