I would choose the Nexus 6P. It is an excellent media consumption device, which is what I would use it for constantly. I would also be able to sell my current phone and get out of owing T Mo as much $$$ for a lesser device.
I would pick the Nexus 6P, being a Nexus 5 owner, I think it is time to upgrade to the bigger screen form factor to get the powerful specs of the 6P. The amazing optics and screen make it the pick for me.