Ikea when the size is available, for reasons I cannot discuss here.

My guess is that is has to do with IKEA's improving smart home trend [0]. I like the fact that the work with all three major platforms so I don't necessarily have to be all in on one if I decide to switch in a couple of years: "Trådfri [has] compatibility across Apple HomeKit, Alexa, and Google Assistant".

[0] - https://www.wired.com/story/ikea-fyrtur-smart-blinds/

It has nothing to do with this. It has to do with details about the OEM for the Ikea product.

Leedarson? (according to http://wastonchen.com/3973.html ) Never heard of them, they make good LEDs?

Leedarson is an OEM for many light bulbs you've seen on shelves in stores.

Seconded that. I switched to Ikea lamps back in the CFL days and today use their LED bulbs and lamps with no problems at all. Of course they're not manufactured by Ikea, but whichever is the maker it seems a very reliable one.

now I'm curious

i've tried a bunch, and the ikea bulbs do the best in a variety of conditions:

- longevity - when used with a dimmer - when a large load is applied to the same circuit

Most other bulbs fail one of those, but I haven't had an ikea branded bulb do poor in any condition.

Do you have preference for a particular line of Ikea bulbs? (Ryet, Ledare, etc)

The higher end line (Ledare?)