And I think something hard for a lot of people to get their heads around is how lighter DTs can be a major problem as well. You'd need a lot of them to rotate through, but the 215 lb kids can cause havoc shooting the gaps if they know what they're doing.
Their height and reach already causes problems for o-lineman. But if you add in a great get off and high effort, you will have a great front four at any level.