I think that people tend NOT to talk about their success with X10 since it's the base standard. I also think that it's natural for us to want the latest technology - let's face it, that's part of why we're here! It's too easy to latch onto the leading edge and "assume" that all will function as described. I believe that it's important to remember that only half of this is science - the other half is the specifics of your situation. What works in one instance doesn't always work in another.
My suggestions are:
1 - start slow
2 - don't invest a lot until the specific technology is proven in your situation
3 - don't jump on the bandwagon of the "next greatest thing" - it's rarely that good at first release.
4 - buy from someone who will take returns if it doesn't work out
5 - read, read, read - ask, ask, ask
I have also had great success with X10. I have a simple coupler (not repeater) and have no problems in about 3 years.