No simultaneous data and voice ... out of the box.
Since this thread has become a clearing house for Verizon-based 6P experiences, I thought I'd toss this tidbit out there. It surprised me the other day when I was on the phone with my girlfriend and she asked me how long it would take me to get across town to her house. I pulled my shiny Nexus 6P away from my ear to check traffic... and I couldn't do it. Then yesterday I was using my 6P as a hotspot for my tablet, and when I got a phone call, my data cut off.
Had I done some research I would've known about this beforehand. It's not a deal breaker for me, but I'm going to miss that functionality. Apparently, you can turn on "Advanced Calling 1.0" for simultaneous data and voice. I'm not sure if I'm going to turn on the feature, as there are some performance trade-offs like calls dropping if you go from LTE service to 3g service. Most of my info came from the reddit thread:
https://www.reddit.com/r/Android/comments/3qcunj/psa_verizon_6p_and_5x_users_activate_advanced/