I have a large noggin, too, and the first-run Edition XS are almost TOO big, if that's a thing. They don't slip around my head with regular movements, but I also can't bop my head to the music too much, even while sitting, or the XS will start dancing, too.
Is it true that HiFiMan tightened the fit on later production runs of the XS? That would be perfect, if so.
The cups are HUGE and have plenty of room, regardless of the production run. No problem there. But the overall fit is pretty damn loose, even for my sizable melon.
The LCD-X 2021 are plenty comfortable despite their weight because the pads are plush -- although a bit smaller than the last-generation LCD-2C pads, which are INCREDIBLE -- and the suspension headband does a very good job at distributing the heft.