If you've got a new Moto X, head on in to Google Play and update your Moto Voice app. An update has been pushed that improves responsiveness for the calling command, PIN code command and YouTube. Motorola's also improved performance when your phone's paired with the Moto Hint Bluetooth earpiece — good timing, as it's finally started shipping.
Plus, there are the requisite bugfixes.
Get your update on at the link above.