Perfectly reasonable e-reader
I agree the ipad could be a bit lighter, but I've found it's fine as an e-reader - the contrast and brightness and font size are adjustable, after all. Where I find it's much better than a Kindle is that it has all the other functions (video, remote network access, mail, internet, maps, etc) in a thin, light, instant-on package.
I also have to agree with the previous poster who said it has a niche as a WC reader ...