Z-wave plus is the newest generation (2015) in zwave. It is also called fifth generation, or gen five, Z-wave. Lots of improvements.
The zwave piece itself is smaller, which means sensors and other devices including it can be smaller, and it also means less power draw.
Along with some other energy management improvements, this should mean for example that battery life is longer. They were really trying to go for a two-year battery life on a Z wave plus door lock. We’ll have to see if they really got there, but they are a lot closer than the previous generation.
Range has been improved pretty significantly. That will help a lot, not just with the actual range, but with the quality of the mesh since it means devices will have more routes available then they had previously, because each device can talk to a wider selection of Other nodes. Fingers crossed, but this may also mean Fewer lost or delayed messages.
Transmission time from the hub to a node will be faster.
It will now be possible to do firmware updates over the air if the device is also Z wave plus and is set up to do that. That’s a nice feature.
Pairing is supposed to be easier, although that remains to be seen.
There are also some network-management improvements which you won’t see but you will see the results of.
So better battery life, longer-range, faster transmission, over the air firmware update, smaller physical device size, lower energy draw, and a bunch of network-management improvements . All good.
This is why I said I personally would upgrade from SmartThings hub V1 to V2 even if the only difference was that V2 was zwave plus.
it’s also why almost all zwaveproduct manufacturers except the really really low end ones will be coming out with new device lines over the next 18 months that shift to Z wave plus.
COMPATIBILITY WITH PREVIOUS GENERATIONS
The previous generation devices will still work fine, so you could have a network that mixes and matches generations. But you need the primary controller to be zwave plus to get full benefits.
If you have a classic Z wave controller (like smartthings v1) and you add some individual wave plus devices to your network, like sensors, the individual devices will still have the improved battery life, and obviously they will still physically be smaller. You won’t get all of the other advantages, though. In particular, you can’t do over the air firmware upgrades unless the controller is also Z wave plus.
The logo looks almost exactly the same except it includes the word “plus.”