and they have IPv6 across their entire network. As someone who does research in this space, and advocates for it as a matter of religion^W principle, this alone makes me want to give them money.

To be fair, Verizon Wireless has been much more successful at getting IPv6 devices into customers' hands.

http://www.worldipv6launch.org/measurements/

  - Verizon: 40.11%
  - T-Mobile: 1.57%

The Samsung Galaxy Note 3 is T-Mobile's first device to ship with IPv6 on by default:

https://sites.google.com/site/tmoipv6/lg-mytouch