When I first got my X10 stuff a few years ago, nothing would work outside of the room where I had my CM15A. Using an Elk signal meter I immediately found out that the biggest "signal suckers" or noise causers (it doesn't matter what you call it, technically it's the same) are: UPS battery backup systems; surge suppressor extension cords (and surge suppressors in general); plasma TVs and stereo equipment; computers; fluorescent lights. We moved not long thereafter, into a spec home that we were able to customize. In order to get a very reliable system, I:
1. Modded the CM15A antenna (per other posts) with a standard FM T-style antenna from Radio Shack: now can receive RF commands from throughout the house and yard.
2. Installed passive phase coupler on the dryer (didn't want to mess with capacitors or the circuit breaker box).
3. Installed X10 signal filters on plasma TV, computers, stereos, and whole-house intercom system.
4. Eliminated all fluorescent lighting except one in the garage.
5. Read past postings to gain knowledge and keep up on current postings because I am now interested.
I'm just starting to play around with Smart Macros, as I have almost no programming expertise. I'm considering adding cameras, although my only preparation is to get rid of my old 2.4 cordless phones, replacing them with 5.8 Ghz Panasonic phones (thanks to Costco's great deals).
I do have the DS7000 security system and it works like a champ (after a little futzing around).
I will say that the one thing that blows me away is how weak X10's manuals are. I would think with a very little amount of effort they could be updated and available on-line. It would save newbies a lot of exasperation.
But all things considered, I'm a happy camper!
Rob