This seems like a good a place to ask about x10 kit since it is a lot more common in the USA than UK. I bought some X10EBa (UK bayonet) Socket Rockets for a friend to allow easy control of house lights.
The units which came are actually marked LM15U and have a clear warning sticker on them not to be used with CFLs. The instructions also say the same thing. The vendor insists that they will work with CFLs but I am suspicious that a CFL load will stress the switcher unit and be stressed itself by triac leakage current and/or switching transients.
I tried looking on the net for x10 guidance and it is as clear as mud. I suspect that the units I have in front of me are not genuine Marmitek but some Chinese knock off copy. It doesn't inspire confidence that the support website referred to in the instructions is repossessed by the ISP and populated with generic search junk.
It does obey x10 protocol and works as claimed with incandescent lamps, but I am wary of recommending going against manufacturers warnings!
It is not a dimming controller so the light is either on or off.
Short of putting one on a test jig and looking at the waveforms does anyone know which of the various incarnations of LM15 are capable of working reliably with CFLs and which are likely to self destruct?
I realise your experience will be with ES fittings, but I am hoping the various LM15 clones exist in both markets.
Regards, Martin Brown