Look under a suspension seat and you'll find more than molded foam over metal springs found on a stock seat. Mastercraft, for example, uses an open weave mesh material combined with rubber strapping that helps to dissipate body force energy when the vehicle encounters a bump. This leaves you less fatigued at the end of the day. A proper suspension seat will hold you more planted, causing you less struggle to keep your body in place. By contrast, an original vehicle seat has more of a tendency to simply bounce you back up off the seat without absorbing as much of your inertial energy.