I don't need an e-reader when I've got books, and an e-reader doesn't really take much less space than a book in a traveling bag.
And I've got no need for an iPad when I've got a laptop which is maybe only twice as big, but has a physical keyboard, flash support, and can do much more for me at the end of the day.
If I sound like an old fogey, maybe so. I enjoy tactile sensations along with my functionality. I was actually one of the quickest to jump on the smartphone bandwagon (but by doing that, I got a smartphone with a very usable physical keyboard