The Xperia Z3v is the Z3 with Verizon branding. Since the logo alone isn't enough to keep customers happy, the carrier also provides them with the largest network in the US and occasional over-the-air updates. Currently it's pushing out an OTA (version 23.0.E.1.44) that hits the Sony flagship with a number of enhancements.
The standout item on the changelog, if you're into Play Movies, is the ability to stream in HD.
Chromecast's screen casting feature works on a limited number of devices, but that list is gradually growing. For now, Sony appears to have cut to the front of the line of handsets waiting to get support. At the beginning of this month, the Chromecast gods smiled favorably upon the Xperia Z3 and the Z3 Compact.
Now at the end of the month, that attention is being poured upon the Xperia Z3v, Z2, and Z2 Tablet.
Today is a good day if you like big, powerful phones, and if you want (or need) to use them on Verizon. The Galaxy Note 4 and the Xperia Z3v, the current flagships of Samsung and Sony, have both launched on Big Red. You can pick up a Galaxy Note 4 for $299.99 with a new contract or a whopping $699.99 without one. The Xperia Z3v is slightly cheaper at $199.99 and $599.99.
Sony releases a new flagship smartphone roughly every other month. That's a complete estimate. Sony isn't on my radar much because its phones often don't usually come to US carriers, and when they do, it's months late. Such is not the case with the new Xperia Z3, which is coming to Verizon as the Z3v later this month.