The first observation is that I see the two devices more as one connected system than ever before. I think this has to do with the screen parity. I’ll write something on my iPhone and push it to my iPad. I might sketch something on my iPad and send it my iPhone.
My iPad and iPhone feel like more of a “pair” now, too. I realized this when about a week and a half ago I started being bugged by the fact that my iPad and iPhone’s Home screens didn’t match. For two years they’ve never matched, but until now I never noticed or cared.