I bought an iPad 2 this year and haven't gone back to my Kindle DX since I got it. The Kindle has a huge advantage in battery life and some advantage in weight

I bought an iPad 2 this year and haven't gone back to my Kindle DX since I got it. The Kindle has a huge advantage in battery life and some advantage in weight, but neither of those are critical in my experience (iPad battery life is sufficient for a day's use, which is good enough for me, and weight is close enough). e-Ink and LED screens each have advantages in some lighting environments. For my purposes (indoors, airplanes, low light), LED works better. The iPad has a huge speed advantage over the e-Ink Kindle, which comes into play for any activity with an eBook that goes beyond "read a page/turn the page". Finally, the iPad has better fonts; especially for technical material, the fixed-width font on the Kindle is incredibly annoying (with e.g. the dot on the "i" near-invisible). [Full disclosure: I work for Apple, but in non-iOS engineering]