I have the same concern. The phone is so large and the display so clear that stealth usage is not really an option. It will be especially difficult for the next few months while the phone is still not easy to get and everyone notices it. There is little chance of discreetly responding to a text or email. Also, make sure you don't get any inappropriate content in the screen because everyone will see it. #
When I'm at work, I spend a lot of time in meetings where I do not have much of an active role. We have an unsaid rule in the office that if you are not a main person in the meeting, then it is ok to use your phone to to respond to work emails and such. However, The phone is so big that everyone notices if you use it.
I was at a street fair yesterday taking photos and every time I whipped it out, someone would ask about it.
It's not the end of the world, but it does require me to be more thoughtful about how and when I interact with my device.