Don't have a Mate 7 as it is so new (just came out in Sept.).

However, the logic is:

If Mate 2 supports AT&T 4G LTE, Mate 7, an upgrade of Mate 2, should do it too. It makes no sense otherwise.
http://www.mindofthegeek.com/2014/09/bwatz/huawei-ascend-mate-2-review/

BTW, the battery life of Nexus 5 is very bad. Avoid Nexus 5 if you can.