The main purpose of the DSS is to provide added support and stability to the power steering output shaft to help protect the shaft bearings. It is NOT intended, or wise to use it as a crutch to stiffen up a steering box already seriously worn.
Since I value added protection for known weak or frequent trouble spots, the DSS was a no-brainer to me - my truck was new when I installed the DSS, and hopefully my steering will continue to function as new...