Hi Madison! The Cascadia 16 offers a Cushion experience in the ride while being able to handle the mountainous trails. This includes a Ballistic Rock Plate in the midsole that not only provides protection from the rocks and roots but adapts to the terrain for added stability. The Caldera 5 offers a higher stack height allowing for a max cushion with an energy return ride. Even though there is no Ballistic Rock Plate, this style is able to handle the Ultra trail.