It seems like it works fine for some people, so you may have no problems with the signal going through the wall, but the cold temperatures in the winter will most likely cause problems.
I have a hardwired doorbell, but since this device is only $50, I think it’s worth purchasing just for the z-wave repeater and mp3 functionality.
If you decide not to use the doorbell button, the Aeon Labs Multifunction Doorbell device handler allows you to repurpose the button for something else like a panic button.
That device handler also acts as a presence sensor so if you use something like pollster to regularly poll the device, you can use it to detect when your internet goes down or you lose power.