I have an old carbon mtb with cups. To mount direct on the CF sounds cheap to me, but I suppose a headset doesn't get the really heavy loads.Bit disappointed with the headset on the Boardman, it started to sound gritty after only 3 rides.
I gave it a quick service and was amazed to see that the cartridge bearings sit straight on the carbon fibre. Is it normal for modern carbon bikes to have no headset cups?
(I had a carbon MTB that definitely had cups).