In the process of weeding down our possessions in general, I've been ditching a lot of books.

Kindle on the iPad definitely works, however the batteried nature of the device makes Kindle on Mac and Kindle on well, a Kindle, more useful for certain things.

I usually actually read on Kindle on iPhone.

Real estate costs so much, I'd pay more for ebooks than the dead tree version. That is an expensive bookshelf to keep.