I like having a large difference in the screen sizes. Large iPad, with a smaller phone. I was using the combo of the iPhone 6 and iPad Mini 2 for about a month and I can honestly say that I used my Mini much less because of the increased size of the iPhone. Then, I upgraded my Mini to an Air 2 and found I use my iPad much more now, and actually prefer a smaller phone with a larger iPad. Having a massive jump in screen real estate from the 6 to the Air 2 is great, and this combo works best for me.
