Why and how is it cumbersome for you?

I agree that reading a book on it isn't the best experience. But I personally just don't read many books anymore. I'm very selective as to the books I read now, as oppose to even 3 - 5 years earlier. And the ones I choose to read, I still prefer them in a physical copy. And I think, generally, people will continue reading (and buying) less books going forward, so trying to create an ebook reader would be a mistake.

>I don't know if it will be small enough to go with me all the time or not.

For me, the thing that'll always go with me (in addition to an iPhone) is a MacBook Air.

>I can say one thing for certain: If it is under $400, I will buy one, no question.

But will you buy a second and third one at some point? Or will you mostly be buying it for novelty reasons? I just don't see an iPad mini being a hit product that generates repeat customers.