I posted this in another thread just yesterday - same topic.
I had a 128gb 6+ delivered to me on release day. Out of contract, and bought it for $950+ tax. I loved the screen - most beautiful thing ever (even better than the iPad Air i think). I used it as my main carry device over the weekend and for two days at work. I did everything I would normally do with the phone - I took it on a long run, brought it out in jeans to dinner with friends, took pictures with it, used it as my gps in the car, and overall just did all the things you normally do with a smartphone. I'm not really into watching movies, playing games, or watching videos on my phone - typically do that at home on my 27" lcd or on the Apple TV connected to a big flat screen.
I absolutely loved the screen. Showing photos to people, and browsing the web was killer. Battery seemed to last forever too. FaceTime calls were great - didn't feel compelled to take out my iPad. Typing was a dream with how big the kb was. But the real downside for me was how cumbersome it was to just use the device casually. I had to consciously think about taking the device out of my pocket. You know those times when you're in a group of people, and want to pull out your phone discreetly to check something and put it away before anyone notices? Couldn't do it, so I just left the phone in my pocket. I couldn't use it to quickly pull up directions to a restaurant, or fire off a quick text message. I noticed going to work that I typically pull my phone out and use it while walking from the parking garage to the office - and I never thought about how I usually do this one-handed because I have to carry my bag, and concentrate on not getting hit by a car while walking. I couldn't do this comfortably or efficiently with the 6+. Using the 6+ was amazing, but required effort. If my phone use was relegated to times when I was sitting down and had both hands free, I'd take the 6+ any day. But yesterday, I picked up a 6, and the device just felt way more natural. I could use it just the way I used all the previous iPhones before it. I'll miss the giant beautiful screen, but the 6 just fit my lifestyle better.