Thanks guys.
I was reading a bit more on this and came across filament bulbs. I thought these were just for novelty Edison bulbs, but the construction is really interesting.
They use lots of smd leds to make the "filaments", and then surround the whole thing in thermally conductive gas, so no heatsink. And the leds are mounted chip-on-glass so each filament is omnidirectional.
And because each led runs at just a few ma, like a cob, they are 110-120lm/W in warm white.
Totally useless to grow with, unless you wanted some sort of micro vertical grow, but really cool technology. Back to gas and glass.
