Which do you prefer: A spork? Or separate knife, fork and spoon?
I for one am not blown away by the iPad for reading. The larger screen size is a benefit, but compared to most eInk devices it's heavy, battery life is shorter, text doesn't look particularly crisp, and the ability to play Plants vs Zombies is at any moment is highly distracting. Smartphones are just too small.
IMO the Kindle and its ilk, while not perfect, is still superior and my go-to device if all I want to do is read.
P.S. I love my spork. But only when I'm camping.