Understood. Personally, I'm willing to pay a little more for piece of mind. I have 4 of the INSTEON garage door kits, and I never question whether it's in sync. If a door opens, the system knows, if it closes it knows that to, and its all triggered as-it-happens, not on a timer. That said, you are correct, most of the time X10 works just fine.
Founder for the CastleOS Home Automation System, featuring Kinect integration www.CastleOS.com