Torque converter diesel auto.
When on cruise control, if a gear change is needed it happens without dropping out of drive like a manual does the moment you touch the clutch.
Auto is far more relaxed to drive in traffic.
Just about every new lorry is an auto now, virtually impossible to buy a manual. When I worked for a coach company in around 2018 they made a management decision to only purchase coaches with auto transmission because the maintenance costs were proven, by the industry, to be less.
No way on the planet will I ever go back to a manual. (But I woukd only consider a torque converter auto as there are no clutches etc to wear out,unlike a DSG or similar. Personal opinion of course)