[tzs]

A coworker and I both replaced almost every incandescent we had with cheap Walmart LEDs [1] about three years ago. That was 26 bulbs for me, and I believe quite a bit more for him.

All are still working fine for both of us.

I went around after installing them and measured their light output. A couple years later I went around and measured again, and there was little or no detectable reduction.

[1] they were a particularly good deal because the electric company here and Walmart had made some sort of deal that marked the 60 W equivalent and 40 W equivalent bulbs down to $0.17 each.

[anotha1]

They are a good deal and I had replaced at least six. My assumption was it's just a manufacturing defect since it's low cost and mass produced. And I'll buy the same ones to replace them.

Also note, these are spotlight LEDs that in the past were halogen, and not your standard sized lightbulbs, which are probably a few generations ahead in terms of manufacturing.

[Symbiote]

The small spotlight bulbs (GU10 fitting) are the most difficult to make reliable, since there's very little space for air circulation to cool the lamp.

As this video says, Philips don't even make these bulbs with GU10 fittings, probably because they can't achieve the necessary reliability.