How bright should gauge lights be??

When I redid my dash a couple years ago I put LEDs in thinking it would be the bomb. They looked great...at first. Within the two weeks they started one by one flickering on and off. Really annoying. After half of them were doing this I finally bagged them and went back to the incandescent lamps. Thankfully I have a daughter with tiny hands to change the inner ones for me. No problems and I can always see my instruments now. I usually run them at about 3/4 brightness.