The reason I would never, and I mean
NEVER buy a Kindle is because I have major concerns about their privacy policy. The Kindle employees believe that they have the right to check on the books that they sold you even after the purchase was completed. If I buy a paperback book from Amazon, I don't give the company the key from my home along with my blessing to enter my house whenever they want and see how that book is doing. Yet, the Kindle's customer support does just that.
I used to have the Kindle application installed on my android phone when one of their employees decided to access my phone without my permission (and he was dumb enough to even write me an e-mail about it). Let's just say that, in my entire life, I never wrote a nastier reply to a company...
Yes, Kobo is slow when turning the page, but it's still faster than me doing it manually with a physical book. In the end, the difference between 0.5 and 0.2 of a second has little impact on my reading experience.