Bill, you sound like one of those fellows who ran into a problem and just gave up. X10 DOES work. It HAS worked for us with virtually 100% reliability since the 70's. Our system has grown to about two dozen Leviton wall switches, half a dozen 16400s, a bunch of plug-in modules, and the irrigation controller. This is all run by an Ocelot. The Leviton pre-set dim commands work perfectly. Even the plug-in dimmer modules work perfectly. They go through the brighten/dim cycle every night without a glitch.
The only recent failure I can recall was one of our switched outlets broke that plastic piece, and had to be replaced. We have a whole-house surge protector, so that probably helps. Over the years I did have to replace a few triacs in the dimmer modules that were popped when the controlled lightbulb failed with a flash. It's a cheap and easy fix.
Some people drive Chevys, some Caddys, and a few pay the big bucks for a Ferrari. They all require some level of maintenance to be reliable. X10 is like a Chevy. If you learn how to drive, it does the job. If something craps out, run down to the local parts store and pick up a replacement for a few bucks. Not so with the Ferrari. But the ride is sweet. And boy, does it give you bragging rights.
Jeff