For melee tanks it is practically a requirement, IMO. The boost to stamina and equip burden gives you a bit boost. If you stack it with Havel's Ring, you can rock the full Havel armor for max poise along with some medium-sized weaponry(well, I have a Zweihander and still keep under weight).
For magic and Dex builds using a Dark Grain Ring though, not so much. The ninja flip ring is key to moving around to avoid attacks and get in quick counters for Dex builds. Magic users will likely have a Bellowing Dragon Crest Ring alongside a Dusk Crown helmet to boost damage. --- "I'd rather betray the world than let the world betray me." -Cao Cao