Originally Posted by jeff-o
Perhaps that's true jur, but I'm not totally convinced. I held both LEDs in my hand, side-by-side, and they were similar, but not the same. Maybe the knockoffs were old Lumileds stock, sold to some Chinese manufacturer for cheap. That manufacturer certainly didn't take very good care of them though, because all of the lenses (which were clear as water on the replacements) were scratched and cloudy.
Oh yes, I forgot about the scratchy lens. Quite right. Yeah, that muddies the picture again... The thing that was a bit of a clincher for me is the detailed shape of the chip base (hexagonal only for the 3W) and the orientation of the LED chip. I thought that a knock-off might show some deviation. Your idea of a cheap reject batch is a good one.
Anyway, now I'm no longer so sure, I think I will see if I can get a replacement just for the hell of it...