A couple of the features of the Nexus 6 that got T-Mobile users excited was the fact that it had support for T-Mobile's band 12 LTE (the 700MHz spectrum) as well as VoLTE and WiFi Calling. According to Des, who's been with T-Mobile for quite a while, it appears that Band 12 and VoLTE are coming in an OTA update this week, likely with the Android 5.1 update. This is great news for Nexus 6 users over on T-Mobile, especially those that are in an area that has band 12 enabled already. Band 12 will give you better signal strength in buildings, it also covers a larger area than the current spectrum that T-Mobile has. Thus making their coverage even better.
VoLTE is also exciting, because it means you'll be making calls over VoLTE, which is where band 12 comes in. Because band 12 is LTE and not voice, it'll mean only better coverage for data. But with VoLTE, it means better coverage for calls as well. Which is great for everyone. If you are using Hangouts and Google Voice for calls, then this really doesn't make a difference to you, just Band 12 does. As you'll get better LTE signal. Those two should be enabled in the Android 5.1 update when it hits next week.
As for the WiFi Calling, Des says that T-Mobile is still working on building it. It's likely a bit more difficult to do since the Nexus 6 isn't a T-Mobile phone, in a sense. What we mean by that is that T-Mobile doesn't have all kinds of backend software installed on the Nexus 6 like they would a Galaxy S6, or an Xperia Z3. And this is also the first time they've had to do this with WiFi Calling, so it's likely going to be a bumpy road. According to Des Twitter account "...WiFi Calling is being developed!". Hopefully it won't be too much longer though.
Those of you on T-Mobile with the Nexus 6, how many of you are still waiting on the Android 5.1 update? How many of you just sideloaded it or flashed the factory image? Let us know in the comments down below.