Users on T-Mobile that own an HTC One, have begun to receive a nice little system enhancement update. This update has been reported to improve the capacitive buttons on the phone, which has plagued users on all carriers, and updates have been sent out accordingly.
This update is still Android 4.1.2, but version 1.27.531.8. Not sure how big the update is, so make sure your on a WiFi connection to be on the safe side. Let us know if you have received the update, and what changes you have noticed. Also, head over to the T-Mobile HTC One software update page for and changes.
Source: TmoNews