I hear ya. As much as I love the battery life, loudspeaker quality and screen resolution, my 6+ is still the worst iPhone I've owned to date. I just don't understand all the hype. So it has a big screen and Apple Pay, big deal.
I was over at my parents' house this evening and my father was having a problem with attaching photos to an email. There was nothing wrong with the phone, he just couldn't manage the task. Anyway, after I had showed him how to do it I had a little play with his iPhone 5. It's my old phone and you know what, it smokes my 6+. Websites load every bit as quickly, the UI is every bit as fast and yet there were no bugs! No spinning data wheel in Safari, no tab reloading, no app reloading, no crashing apps, no screen freezing, no copy/paste bug, no portrait/landscape rotation issues.
It felt like a much improved version of my own two years newer phone, but just with a smaller screen. I remember it being like that but after several months of not playing around with it I had got used to my own Bugmeister. Just not good enough Apple.