Final Fantasy XIV Database - Ffxivpro.com

To be simple and directly answer the OP: Heca Harness is best suited to multi-hit weapon skills considering the significant accuracy and STR boost. So to be particular, THF & DRG I would say benefit from this the most (ie: Penta Thrust, Skewer, Drakesbane, Dancing Edge, Evisceration). However, it's a great WS body piece for any job that can use it to assure your WS lands accurately and ushers past mob defenses via STR increase.