Bezels have the opposite effect to what you are purporting. The most difficult to reach places on the iPhone 6 are the bezels. A 6 inch phone is not one-handable imo. That is coming from someone with larger than average hands.
I can't say enough good things about them - for $2 they transform even the largest phones to being one-handable. It's miraculous. They make this conversation obsolete without the slightest exaggeration. They systematically prevent fragile holds and - they're cool,
The ZenTouch button on this looks great - main complaint with my Mini is not being able access Notification Center easily one handed. Unfortunately it looks to be right hand operable only…
Yes I use a powerbank on multiday backcountry trips, but it stays in my pack, not on my person and especially not in my hand.