still have the Beckman world tour set of 4 , that were from the days when Bob and BruceGordon were co producing and they were made to fit Bruce's racks.

Strap and buckle mount is rock solid .. they are a complicated insider knowledge to fix and remove them, but that makes them very theft resistant.
Compartmentalization was good on tours ..

at home I like the bucket open space of the Ortliebs. for grocery runs and the like ..