Sprint is actively rolling out an update for the HTC One (Update 1.31.651.2) that will be granting the ability to place HD Voice calls. Updates for other devices likely to follow? Specifically regarding HD Voice only; I'd love to hear from some users that have the One with update and can place an actual HD Voice call (2 x HD Voice capable phones connected to Sprint's HD Voice capable network) Up until now all we have seen or heard is demos from over a year ago. How is the call clarity on the wideband Codec? Any marked improvements in ambient noise cancellation?