I just received my Plus today. I love it, but the limiting factor for me is the size, for all the reasons previously stated. Truth be told, if the 6 had OIS I probably would've gone with that. My sweet spot is a 5"-5.2" screen, 1080, with OIS. It would give me the screen size I crave with the portability I want. The Plus fits in my suit coat chest pocket and my trouser front pockets (even sitting), but I think it is too long to carry in my jeans and be able to comfortably sit down. Finally, while I do most of my composing/typing on even my iph 4 with both hands, I do frequently check messages/email and answer calls one handed, and I just dont think that is functionally possible with the Plus.
I will probably stick with the Plus for a year, and next year maybe downsize to a 6S if it comes with OIS and maybe improved screen resolution.