Hi folks. Jut wanted to share my frustration and final decision here. Insteon sucks and I'm dropping it in favor of Z-Wave.
I don't have a complex system nor home, just a handful of devices in a small single family home. I have had some fairly reliable automation with Insteon over many years but it required boosters, filterlinc and ocassionally gave me fits of problems and difficulty. When things slowly became unreliable and then stop working, trouble shooting has also been very difficult. Both the ISY team and Smarthome folks have provided some support on the issue but recently resolution just did not seem possible (and I am incredibly persistent...). I had a pool pump go from reliable, to spotty to nearly unusable. Tried some Intermatic ET-NF noise filters (multiple) as the last step and still a no-go. Whether the pool pump itself, LED lights, toothbrush chargers or whatever, the system should be rock solid reliable against these forms of interference.
Based on a Z-wave whole house fan setup I added a few years back, and it being rock solid reliable, I have decided on Z-Wave
Luckily the new-ish (at least to me) GE Outdoor 240V Smart Switch with antenna solved the problem of no electromagnetic signals penetrating a metal enclosure.
Obviously, for all of those folks with great/easy/reliable Insteon systems, great for you (sincerely!). I simply could/would NEVER recommend this system/protocol for any one new to home automation, handy and experienced with computers/electronics or not.