I switched from a 5S to the SE when it came out because I just did not like the 6. The size, how everything was round and it easily slipped out of my hand. I handle a modern iPhone at every opportunity that I can, Apple stores, friends, colleagues and I like them less and less every iteration. I don't get the appeal of wireless headphones (another item to charge, easy to lose, poor sound quality on the affordable ones), they're heavy, I really need both hands to use them, they're awkward in the pocket or used a phone, holding the thing to your ear...
What's having an SE like? Except for some apps (mostly Apple ones) clearly not being optimized for the small screen, it's great. Does not slip out of your hand (I never use a case), you can rest it on its side for selfies, group photos with the 10s timer, just put on a shelf during Facetime calls to be at eye level with both hands free (I do that a lot while cooking or getting ready in the bathroom). I charge it while using the earbuds in bed, I can charge it up a bunch of times with the tiny power bank. I enjoy the step counter, touch ID, live photos, the camera, the 2-tone flash.
About once a year I remove the lint out of the charge port and the headphone jack with a tooth pick so the ports work as on day one. I changed the battery for the first time recently. Apple would have needed the phone for about a week and that was a no-no for me so I got the kit for 25 EUR and did it myself, easy peasy. I'm holding onto it as long as I can.
The only thing I don't like about the SE is that the power button has too much clearance so it wiggles around a bit, making a mechanical buzzing sound when it's vibrating. Apple learned from the 5S and gave it just a bit more clearance. I wouldn't mind the taptic engine with 3D touch, but that's apparently getting out of style anyway and few apps implement it in a meaningful way.