I like my large folders (Manix in particular) for heavy cutting chores that are not "hard use" situations - like breaking down 20 cardboard boxes to take to recycling. I could use a smaller knife, but that large folder has plenty of blade and is quite sharp - it takes up a good portion of my jean pockets, but isn't too large to carry (and its a very large folder).

I don't like large folders for their toughness - more for the amount of usable cutting edge.