High waterlevels
What some might not take into account is that these tubs are "only" ~2cuft while a normal US FL starts at 3,5 or upwards.
With a drum more than 1,5 times as big, one needs 1,5 times as much water to reach the same level.
And these use between 15-20 gallons for an 8kg (something like 17 pound load) and deliver quite good results, though the German Eco cycles go down to as much as 10 gallons for the same load.