Readability on iPad Air? [View all]

I'm considering getting an iPad Air. One advantage in our household would be the ability to read magazines on it and avoid dealing with all the paper.

I'm wondering, how is it for readability, comfort while holding & reading, and eyestrain (or lack thereof)?

I also have a refurb B&N Nook, which I like because it has an E-Paper display that's very easy on the eyes. I assume any light-emitting device like the iPad would be more of a strain, but wondering what you all who have one think of the iPad Air experience in this regard.