Insteon is still X-10. While X-10 transmits it's signals via PLC's, the Insteon line transmits both PLC and RF signals at the same time for more reliable operation. The Insteon devices also act as repeaters, so theoretically the more of them you install on the system, the better the reliability of the whole system. I have not tried Insteon yet, the X-10 stuff is expensive enough!
A couple minor points there--Insteon isn't X-10, though most or all of SmartHome's current Insteon offerings also support X-10. Also, the only current Insteon device that supports the RF version of the protocol is the repeaters; everything else currently offered uses the power line to communicate.
The Insteon protocol is different from X-10. It was designed to correct all the major deficiencies of X-10, which they appear to have done an excellent job of. The controls operate instantly from a human point of view, rather than with a delay as X-10 does. The protocol is bidirectional, with acknowledges. It is therefore very reliable--the controls work first time, every time. They've done away with the House and Unit codes of X-10; instead, you just link a dimmer to a controller by pressing a button on the dimmer.
Being a bidirectional protocol, there is the possibility of using these devices in very sophisticated, computer-controlled applications. There is in fact some pretty sophisticated-looking control software out there already, but I haven't dug in and found out what it can do.
[This message has been edited by SolarPowered (edited 08-31-2006).]
Thanks for the correction. The X-10 home site pushes Insteon so I thought they were the same mfg. I guess I should try some Insteon products, I have had a few really irritating issues with X-10. One house I had to put filters on all the LV lighting to get the X-10 to respond reliably, plus install an expensive coupler/repeater. Now the customer informs me that the dimming controller I installed for the wall sconces is turning on the pool light, which is on a manual X-10 switch mounted out at the pool equipment. The Unit and house codes are different from the ones on the dimming setup. Don't know where to start on that one.
Smarthome, the parent company of Insteon developer SmartLabs, has also been making X-10 products for a long time, so your confusion is understandable.
All PLC technologies need to somehow bridge between the two halves of the 240V line. Your X-10 system is using a repeater/coupler; Smarthome is currently recommending using two of their RF repeaters for that function. Frankly, that's the one part of their current Insteon offerings that I find less than optimum. I don't want the system relying on two gadgets that are plugged into receptacles; I want the bridge hardwired into the electrical wiring so that you can't kill half the control system by pulling something out of a receptacle.
Except for that point, Insteon is designed to fix all the X-10 problems you're having. The Insteon protocol uses a Cyclic Redundancy Code (CRC) to detect transmission errors, so you don't have controllers switching the wrong lights. It also uses positive acknowledgement and resends the command if it doesn't get the acknowledgement, so there's no flakiness--the controlled light operates correctly 100% of the time.