After directly comparing my coworkers' 6 and 6+ this week, I remarked that I might opt for the 6+, since one-handed use is effectively out for me even with the 6.
It's a built-in feature called Reachability. I've tried it and it feels like a bandage at best. I imagine getting accustomed to it would probably help, but it slows things down quite a bit.
(And the phone is still quite wide, which may be a less bemoaned issue than the distance of upper corners, but is still an issue for me.)
After directly comparing my coworkers' 6 and 6+ this week, I remarked that I might opt for the 6+, since one-handed use is effectively out for me even with the 6.
Relatively small hands be damned...