When I read the first rumors about two larger iPhones I decided to get the 4.7" as I thought that all the Android phablets looks rediculous. Then as the Keynote ended I was certain to get the iPhone 6 Plus
Now, I'm not so sure

...
A few years ago, before the large screen craze started
we were all obsessive about the weight, what happened to that? As nice as the new iPhone 6 Plus is, I think alot of us will grow tired about the weight of it, it's almost 180g! That, combined with the physical size makes it a device that you for sure will know that you have in your pocket
I'm pretty sure I'll go with the 4.7". I'll always hate that I didn't get OIS but I'm sure It will be added in the iPhone 6 S. Screen size is fine, when I need a larger screen for browsing, reading magazines, watching film and productivity I'll use my fabulous iPad Air
To me, a phone should be light and inobtrusive. It should be a device that I always cary with me, no matter what. I'm afraid that the large and heavy iPhone 6 Plus will be left at home every now and again and that my current iPhone 5 will continue to give me service. When I'm at home or on a plane or train the iPad is the best device for me.
Added to this equation is the new "hand off", I'm still tied to a laptop at work and iPad at home, the 4.7" will slot in nicely between them. The iPhone is a complement, not a replacement.
...and remember that
a gentleman doesn't flaunt his assets, discretion is a sign of good manner