I have used Lightwave RF switches a few times and they have solved some wiring problems. I have not tested the limits of the range, I think 30m, at all just local switching in domestic premises. It is convenient to be able to place a battery powered switch anywhere, but you do have to change the batteries occasionally.
I find that the general problem is where you can place a receiver relay so that the connections are enclosed without making huge holes in ceilings (that must still be accessible to link the relay). Though I did fit a small access panel in one ceiling where there was a lot of kit to fit in the lighting circuit.
I do feel they are a bit of a gimmick but having said that they do seem to work, but the cost is a bit silly as yet. Though if you are installing an entire network of controls for everything the convenience may justify the cost.
