In my experience there are Debian admins and Ubuntu users - hence explaining why more Ubuntu users use proprietary drivers and why Debian admins tend to avoid default groups of packages, choosing only the ones they need.

An Apple engineer explained that the reason Apple charge a premium over other suppliers for extra hard disks and memory is that:
1. They validate the part.
2. For hard disks at least, no two disks shipped with your Apple machine will have the same lot number. The idea is that this reduces the chance of multiple disks from a faulty batch going bad at the same time.