I got my 6 Plus today and I absolutely love it so far, but the one "gotcha" moment that I experienced was when I went to listen to Spotify on my walk to the store. I quickly realized that the Plus is not nearly as good a music player as my 5 was, because I can't quickly whip it out of my pocket and navigate my playlists with one hand.
I still love the device, but I'm giving it a week to see how it holds up in various real world situations. Tomorrow morning, the Plus goes to the gym
There are so many pluses (pun intended) to the larger screen though, and so far it's a joy to use. Just a matter of weighing the pros and cons.