Ditto on the JVDE's XTB-IIR. X10 is a simple, cost effective setup and the XTB-IIR is the icing on the cake.
I've been using X10 30+ years to control high-load appliances in my home to take advantage of the lower TOUD utility rates. Once I found JVDE's XTB-IIR unit, I never looked back. I removed all my "passive couplers" b/c the XTB-IIR solved nearly all of my X10 communications issues with the exception of "noisy" florescent lamps. Now those all have filters and I'm a very happy X10 "old timer" Later!