HED. Wheels are build with industrial standardized ABEG5 (quality norm) cartridge bearings .. these are sealed and greased for (their) lifetime and there is nothing to adjust .. just ride them .. mine do not even make vibrations on the handlebar or frame when the wheels running freely .. after 25k mls ..
Well, on the other hand I had a Jet front wheel some 10 years ago where the bearings wore out within a few hundred miles. Admittedly this was during a stage race with brutal weather and pouring rain day after day. One day one of the top riders on another team rode up next to me and said something like "I know when it's you on my wheel because I can hear you". It didn't make sense at the time but a day later I happened to swap front wheels and realized that my front wheel bearings were seized so tight that I could barely turn them with my fingers. My wheel sounded different than the others due to bad bearings.
Yeah, ABEC 5 bearings are sealed for a lifetime but that lifetime might only be a long weekend if you're racing in pouring rain on gritty roads. For what it's worth I wore out an Ultegra chain in just a few hundred miles over those same few days. And barely staved off hypothermia for that matter.