I'll throw in my anecdotes. Used to be a sysadmin at a "Rather shiny" east coast university.

Mixed bag. Some IT worked extremely hard, carried whole group, others did almost nothing. I have stories about coworkers that make WoW look positively productive as a workplace activity.

Same went for admin staff. A few of them clearly did 90% of the work, whereas a few did almost nothing. (and this was widely accepted and known)