In the current meta, 35 VIT. Strength and Vitality scale the same post-3.2, and Vitality affords you more health at the same time as giving you identical bonus damage to Strength. It's silly not to spec Vitality now. Every tank should.

The most important thing to note, though, is that on any i220 or higher Vitality accessory, you should absolutely be melding Strength. It's far and away the best stat for that slot, since you can't meld on more Vitality, Accuracy exists in spades on tank gear, and every other secondary is strictly worse than Strength by a long shot.