I can never go back in size from my 6s Plus. I was one a few years ago who did not want to move from the 4s size but big is 100% better.
I own a 6s plus, iPad Pro 12.9" and a MacBook Air 13" which is the best range of products I have ever owned. Each have their good points but none can do without the other in my world.
The only thing that would get me to go back to a smaller phone would be financial constraints beyond my control. But I'll fight tooth and nail to keep the Plus size iPhone going forward. That SE is a cute little bugger though. It'd make a great second phone to carry out on the boat.