You could also take a look at the system "Digitalstrom" for your application case. No radio, everything modulated over the normal, existing wiring. It's a bit more expensive, but works perfectly for us - including smartphone app and so on.
Isn't there anyone who has installed the Gira System 3000 and can report about it? After the initial research, it is also our favorite, as we also prefer the other switches and sockets from Gira.