Thanks for all the great input, this thread was helpful not just thinking about Apple devices, but how folks USE their readers of different sizes. In the end, I decided to stay on same (Android) platform in my case, and got a Huawei M5 8.4" tablet, it'll do what I need and the screen was large enough to view single pages of code in programming books, which is my main use besides e-reading and browsing the web. It was also at $289 a bit cheaper than most Ipads I could see

, although in my case that was not the driving factor.
For myself, I also noted the 8.4" screen was a significant improvement in readability over the 7" Google Nexus tablet I'd been using for several years. That extra 1.4" of real estate made quite a difference.