My Internet service is almost flawless, no drops or sags in speed. I get a consistent 40 Mb down and 10 Mb up with a ping of about 45 ms. Wi-Fi overall a very good and many of my devices run a wired connection. They all communicate with the echo without problem.
My router to show all the signal strength and the lowest one is 4 Bars except my sprinkler system which is 3 because it is quite remote. The echo shows a solid 5 Bars, the echo only sits about 10 feet from the router.
If you look at some of the Insteon forums communication failures between the hub and the echo is a common problem and appears to be an issue with the hub itself. That's why am thinking that maybe the ISY will solve my problems.