LonWorks is as solid and robust a system as exists for the very difficult communications environment of the AC powerlines. It is in use today in power metering world wide. I have designed with it and applied it in households across the US. It has a very basic problem in gaining acceptance for products that the homeowner will purchase. The functionality you can buy in an X10 product for $10 will cost you $40 in LonWorks. For the simple things the homeowner wants to do for himself the premium is just to great. This religates lonWorks pretty much to devices that are installed by other than the homeowner where the cost is not so appearent such as the utility, the community, or a contractor installing an extensive home control and/or entertainment system. Powerline Carrier itself is just problematic enough to irritate enough first time users to have never overcome it's initial reputation as unreliable. In the hands of knowledgable installers it can work very well. It is just not a high confidence plug and play solution.