Water level
When HE front loaders first appeared and the water level did not go up the window, I did not believe they could clean. Through direct experience I have learned that, contrary to what I thought, the lower HE water level actually cleans better, counterintuitive as it might be. If the water is deep and up the window, the clothes only roll around in the water at the base of the tub. In an HE FL, the clothes are sopping wet, much more so than they appear while tumbling, and they fall and slap on the tub, which forces water and suds through the garment much more effectively than when the fall is softened by standing water in the old school FLs. It's the same washing principle as the tried and true centuries old method of repeatedly slapping a sopping wet and sudsy garment on a smooth stone. However, if there are too many suds, the clothes will not get clean because the excess suds break the fall and impede the flow of water through the fabric. Also, the new HE FLs do not tangle and ball clothes up because they alternate clock and counterclockwise rotation. Clothes tangled and twisted up will not get clean because all surfaces are no longer exposed. The new HE FLers are totally superior to the old school ones. Now that I've had an HE FL, I can see that people who complain about poor cleaning in their HE FL are using too much detergent and/or overloading.
JMO... ...for what it's worth.
