With this new level of efficiency/efficacy I think nearly not so much heatsinking would be necessary. Anyway, how does one heatsink filaments effectively? Thermal path from the bottom to base does not look good, and from the top, not good at all.(Looks at the 60W incandescent equivalent Philips 'alien head' sitting on the desk rated at 12.5W)
Yeah, probably something to do with heat dissipation.
So what is the primary cooling mechanism? I found one smaller A15 60W eq. (7W) filament bulb uniformly warm across the glass bulb after being on for an hour or so. Somewhere I recall hearing about convection inside the bulb transferring heat to the envelope, which seems to fit.
I kept an original 60W "alien head" bulb using blue LEDs, and later 75W version using white LEDs. Those required big heatsinks as majority of power was going into heat. They are exceptionally well built, but heavy, large, and expensive at the time.
I saw the 2700K Philips bulb on Amazon Canada for around CDN$30, too steep for me.