I guess the question from me is, what does "virtually 100%" mean? Is it safe to say that any X10 system can only approach 100% reliability?
Also, I would think that any configuration that uses wireless modules (like DS10As, or MS1XAs e.g.) cannot work reliably 100% of the time because their is always the possibility that two or more transmitters could step on each other during transmission.
"Virtually" to me means everything works all the time as near as I can tell. Before adding XTB there was one CFL table lamp in the living room that missed its "off" command a few times a year. Since adding the XTB, the only "failures" (a light not coming on when it should) have been due to burnt out bulbs. I can't recall anything not being in the correct state.
Of course, this house was designed to be X10 friendly. All X10 devices are on the same phase, and most CFL ceiling circuits are isolated with filters. And we have strong signals throughout.
Since there is the possibility of a collision with multiple sources, the Ocelot pretty much runs everything. The only motion detectors we have are either for direct 120V control or are hard wired into Ocelot digital inputs.
Ah, that does bring to mind one X10 issue. We use Leviton 16400's to trigger macros in the Ocelot. Some of those send a lot of X10 traffic. A second 16400 command while the Ocelot is transmitting can cause a collision, so, I just don't do that.
For example, one macro sets up an irrigation cycle for the next day, and illuminates the 16400 LEDs for the zones scheduled. If I also want to trigger a particular zone NOW, then I either do that first, or wait until the LEDs have been switched on.
Jeff