Just adding my 2c. Before the rumor mill got going months ago I was hoping apple would go to a 5-5.1in phone similar to the Galaxy S4/5, but of course they went .4in smaller and .4in bigger so I was left with a tough choice. I considered both VERY seriously before making my decision and picked up the plus.
When I first started using it there was a definite omg what have I done feeling as I went from a tiny 4.0in phone for a phone that's bigger than a Galaxy Note. However, just 2 days of use later and I'm loving it. I've adjusted how I grip slightly, but 1 handed use is not a problem. When playing games, browsing the web, watching videos, etc it's just amazing. I have a full size iPad and already see myself using the 6+ in situations where I would have felt necessary to snag the iPad before. My big worry was a non issue, it fits in my shorts, jeans, and work pants with no tightness or bulge or pressure on the phone when I sit.
I was changing settings on my wife's 4.7in and while it's a great phone and perfect for her, I couldn't get over how much smaller it felt, I can't even imagine touching a 4in iPhone 5 at this point!
Not pushing anyone else any direction, the 4.7 was perfect for my wife, she loves the extra size and it's still very comfortable for her. I have no regrets I purchased the 6+ and the few if any usability and portability sacrifices are more than made up for by the beauty of the large crisp screen when using the phone.
Thanks!!