Adjusting to using the 6 plus was not a problem. The screen resolution is beautiful. The battery life is incredible. OIS on the camera works great. But it has become burdensome to lug around. And mine lags. I rely on my Apple watch as much as I can.
When the S series comes out it is my intention to downsize to the 6s and trade in my 6plus. That's just to ease the burden of carrying it around.
I agree with this.
The display is an absolute upgrade over my previous iPhone 5. And battery life is what I like most: I get almost double the battery life that I got over the iPhone 5.
It was very easy for me to adjust to its size and it fits in my pants just fine. But whenever I am more active (like when you're sporting), it becomes more troublesome to bring the device along.
Additionally, it's basically impossible to have a 'sneak peak' at your lock screen without anyone noticing... it's too big for that.
Maybe the 'iPhone 7 Plus' will have smaller bezels, which might make it more mobile.
Also, there are some
performance issues in my opinion. First of all, sometimes there's the occasional lag. I very often play music and when I switch between apps - sometime - the music and animation stutters a bit.
Secondly, multitasking is subpar compared to the older iPhone 5. If I am lucky, it holds two apps in its memory - so that I can continue in an app right where I left off. But very often, the app reloads again when I switch between apps. I believe this issue mostly exists because it only has 1 GB of RAM, while it is pushing many more pixels than the iPhone 5 (and iPhone 6).
The iPhone 6 doesn't have these issues, which makes it a lot better for power users in my opinion.
I'm definitely considering going from an iPhone 6 Plus to a regular iPhone 6S this fall. Why? To get better performance and higher mobility.