In regards to the iPhone, where I can compare my use of Instapaper, the [Kindle’s] screen really makes a big difference for extended reading. But the biggest advantage is the Kindle’s lack of any good use other than reading. When I pick up a Kindle, I read.
5typos.net: My Kindle 2 review (before the reality distortion field)
I use Instapaper to read on my iPhone (until my eyes start drying up), but I often switch over to send texts, take calls, or play Words With Friends (jagiddens). When I’m on the Kindle, I don’t even try to do anything but read, which is what makes it such a great experience.
(via marco)