Works great, but you have to adjust your wiring
Reviewed on 01/02/2018
These work great, but are quite confusing for the average home owner. Regular 3-way (and 4-way) switch wiring uses two power wires going to/through every switch. (Ignoring grounds and neutral for simplicity, for two 3-way switches, a pair of wires goes between them. One at a time is "hot", the other is not. Flipping the switch at the "power" end changes which wire is "hot". Flipping the switch at the "output" (light) end, changes which wire the output/light is connected to. Any 4-way switches are added in the middle, and swap the two wires mid-stream.)
These GE Z-Wave/Bluetooth/WiFi switches are wired completely differently. Power is switched on/off ONLY in the main switch. The add-on switches need two wires (plus Ground) - a neutral (shared with the rest of the electrical system), and a "traveler" (from add-on switch to the main switch). Additional add-on switches are added in parallel to the first one. The "traveler" has only a low-voltage signal on it; it doesn't carry power. I'm uploading a diagram to make this more clear. Hopefully it will be visible from my review.
Works well once you figure it out
Reviewed on 03/26/2017
I had a little trouble finding which wire was the line from breaker box, but once I did this was easy to put on the remote switch. Easy to use these GE switches with Samsung Smartthings. My only complaint is that I use the blue light on the normal switches when the lights are off, as a night light - wish this had the blue light.
Reviewed on 03/16/2017
I have a few of these now and love them. I have them paired with SmartThings and my automation works 100% of the time. I love them. I only wish they were a bit more stylish. They are very bland looking. The 3 way switch setup is a bit confusing as you are capping the black wires together on the add-on switch but if you are comfortable following directions you are ok.