It's one of those things you don't realise or appreciate until you get it, then you get so used to the new status quo that you can't go back to anything worse.
And yet, when I'm holding my wife's 6S I think "Whoaaa slippery bitch (no, not you, my wife...)! Can't properly hold you with one hand!" And then just second later I say to myself: "Yeah **** it! I'm sticking with my 5S which has the perfect weight/size balance."