In patch 2.5.5, equipment writs were changed to use only the top tier refined materials.
When One-Tamriel arrives later this year with its overabundance of top-tier materials available for harvesting, it makes sense to make this change. However, the equipment rewards, in their present form, are “a kick in the stones”: 664g, 1 Intricate / Ornate item, 1 trait item, and a rare chance for a Glass Motif Fragment/ Repair Kit / Survey map that leads to nodes that contain a mix of top-tier and the ones below it.
As it stands now, the opportunity cost of the mats (make more selling as material or crafted goods) have more value than the value of the writ rewards. Unless you have a hoard of mats and looking for source of inspiration points, I wouldn’t recommend doing the equipment writs.