My mistake, I thought you meant cartridge style The xtr uses a sealed cartridge bearing pressed into an aluminium cup. . . . I think. The bearings themselves are sealed.
They aren't cup and cone.
Can anyone confirm, I am basing this on my dura-ace which I believe is the same.
The confusion arises when "sealed" refers to a couple of elastic type bands to stop dirt getting in!
These are double sealed apparently. I am guessing that means cartridge bearings PLUS a rubber seal of some type!