There's always SE. Sturdy, proven design, headphone jack and sane (one-handable, pocketable) size. As much as I'd want to like Android, there's nothing of this size left there. I hope Apple will continue this line into the future.
It's fast and the battery always lasts 2.x days to me, I charge it again at around 20%. It lasted 3 days 18 hours last time over a long weekend, down to 9%. I checked and I made 8 hours of screen activity so it wasn't in my pocket all the time.
Given how long it lasts I wish they traded some battery to make the phone thinner and lighter, exactly as the SE.