I've had a JVC El Kameleon headunit in my Insight for a couple years and haven't had any problems with the ECU. I can't really see how it can because it plugs into the same wires the factory one did. Maybe it's a problem on newer Insights or one's with a certain option. I haven't heard any of this myself, though.
My Pioneer and my ECU work great. Second thing I did on the Insight when I got it home (after a practice tire-changing drill, manual in hand... a habit I have used with every new car, since a flat invariably happens at 2am some windy, rainy morning and then's no time to learn your new car's vagaries) was to take out the Honda head unit and put a decent head in.
Sounds to me like "a lot of people" are misinformed... :lol:
And yes, I still have the brand-new original Honda am/fm/cassette and if anyone wants it, email me privately, for less than about the price of a weekly magazine subscription I can be convinced to part with it... :shock: