Recently the battery on my daily-driver 6S ate it, so I purchased a cheap backup SE to use for a week during the interim.
It was interesting that I liked the SE best when the screen was off. It’s a fantastic size for holding and ergonomically. The problem is that Apple is clearly optimizing the OS for larger screens now, so a lot of things look and feel very cramped on the SE in ways they didn’t used to (5 and 5S). If Apple prioritized the size it would still work fine, but they don’t, so it’s frustrating. And typing was a mild nightmare of constant mistakes.
All told, going back to the 6S was an overall relief. It’s not a size or shape that has ever been ideal, but the added width makes all the difference.