Big screens for eyes. Small screens for hands.
Quick question - does anyone else think the differences (OS and app UIs) is actually greater now between iOS and Android than say OS X and Windows? Having both Android and iOS phones and tablets, I'm surprised people jump across the aisle as often as they do. It's like when a slick Sony ultralight or solid as stone Lenovo T-series comes out - you boot it up and it's.... still Windows.* Maybe I feel Android is a larger UI disaster than many (and a phone UI more important), but surely you start to like one mobile OS over the other, no? What hardware spec beats that?
* or Linux... and there are certainly those that prefer (or have to use) one of the three OSs to the other. Same question.