Considering we won't be seeing anymore gear until whenever we get Defense Quests or actual content there isn't really any downside to investing in NGS units + weapons since it's braindead to farm materials anyway. The defense gain you receive from units and the power difference from preset ability can make it a notable upgrade for the time being. With easy enough affixes to make you can make units stronger than your old Cras set with Zeont units. Weapons and rarities seem to be tied to levels anyway so until Winter comes with the level cap increase there isn't going to be anything new so you'd reaccumulate any spent resources anyway if you play the game at all.