50 VIT and Mask of the Mother gives you 1650 HP. Adding the Ring of Favor and Protection to that gives you 1980 HP. Assuming you're not gouging END (40 END max), is it worth sacrificing 330 HP in order to ninja flip or would you rather sacrifice poise?
You can easily have enough poise (35 with Havel's Gauntlets + HSW) while still being able to use Ring of Favor and Protection and DWGR, so I see no reason to ever use the Wolf Ring except for some gimmick builds.
You need 36 poise in order to tank a one-handed hit from a greatsword. If you use MotM + Dingy + Havel + HSW then you most likely won't be able to use a shield or even a weapon that weighs more than 6.8 units.
Also, it's just as easy to get 36 poise, although it is not that much of a necessity as having 31 poise. And I'm really not worried about getting hit by a greatsword r1 mash. You can just toggle escape to parry them all day long.
PSN/GFWL: Jemoai http://www.youtube.com/user/Jemoai <--- Dark Souls stuff