We have had a NARCO 12D in our C150 for 10 years. Works OK except that the display is replaced every 3-4 years because it stops working.
It usually starts with the left digit "1" in the active COM-frequency.
This indicates, that the whole display will become black in a few weeks, and it is time to get your avionic shop to order a new display.
Our 7 year old KX165 is starting to lose it's left "1" now. ..
This never happens to the display in my 150$ car radio
.