I would bet the large bagger shown in that video says something about only being used to vacuum up DRY LEAVES. Because when I try to bag grass, with my NORMAL sized catcher, the bag can get very heavy. I feel if you doubled the size of the bag and used it for grass it would make it too heavy for the mower to pull, as well as too heavy for you to take off. But for dry leaves, yes it would come in handy because the mower bag fills up quick with leaves.