The main reason I've been after these particular duffels is that the large (32" and 26") models
fold down to nearly flat 
The "foot" (the part that the bags stand on when upright) folds so that when the bag is packed, it will stand on its own just like any other piece of luggage. BUT when empty, you can fold that foot (end) part down and the whole thing will slide unde the bed! So even if we have 3 of the large and medium bags, they'll all flatten down and slide under the bed, saving us precious closet space!