Great phones as they are, just not commuter friendly enough for me. Get a call when your trying to make your way off a bus and fumbling around an inside jacket pocket is just a nightmare.
If I was someone who just jumped out of a car and went into work, the 6+ would suit me fine.
Another issue is when I take my kid to the park, it's like having something extra to be concerned about. I pick the kiddo up and have this huge phone in my pocket i'm worried it's going to get squashed or bent. Want to take a fast quick pic, you need to make sure you've gripped it right.
6 is the only option for me. Even the HTC One M8 felt a bit too big for daily use, and that's far smaller than a 6 Plus.