While Verizon gets the Nexus 6 tomorrow, Sprint's version receives Android 5.1 starting today
Verizon's Nexus 6 comes with Advanced Calling 1.0 which means that users can take advantage of HD Voice Calling when connected to compatible Verizon handsets. In addition, voice and data can be used at the same time. Lastly, Verizon's Nexus 6 comes with Android 5.1 pre-installed.
Speaking of the Nexus 6 and Android 5.1, Sprint subscribers who own the handset will start receiving the Android 5.1 update today. The new build will bring Lock Screen notifications, a new "Recent Apps" menu, Material Design, the 64-bit ART compiler (allowing for faster opening of apps) and Project Volta (for longer battery life). The update also fixes a problem that had duplicate SMS messages going out, and includes enhancements to those sending MMS messages to the U.K. It also offers protection against an accidental Factory Reset.
When you do receive the notification that your phone is ready to be updated, make sure you are connected to a Wi-Fi network before starting the updating process. And you should also have your battery charged to at least 50%.
source: Verizon, Sprint via AndroidCentral, AndroidandMe