Knights vow/Should I go back to playing full tank, tank support?

After seeing the stats changed (twice if i'm not mistaken). This item isn't an item that just gives you raw stats for cheap. For tank supports its important because of the VOW itself. What we have now is an item that heals for 12% of damage your partner does, but ALSO does 12% of the damage they would have gotten to you instead. Now that's not too bad on some champs like naut. Because I have an over shield to absorb that and I start fights when I see fit to make a pick. But what about braum? No heals(alistar), no over shield(naut), but he has some resistances and a shield. VERY good tools, but they don't help true damage...

Now the item has 250 health (down from 400) that's essentially 150 less true damage I can take and 40 of the 0 armor is useless if, (and I pray I don't) I get caught out or roam. But its cheaper by 100 gold! I hear you say. Well that's fair... except that on non-tank support items 100 gold is only worth 37.5 ... meaning we lost 112.5 health with nothing to make it better for supports (making that 12% value higher or adding something to it). True that supports don't get much gold, but were not so poor as to not have 100 extra gold. I get that top laners and junglers could but this item and you would have heck to pay since it was cheap and provided excellent stats for the price. But when push comes to shove who in their right mind would buy and item that gives you a ruby crystal and a third of health that does TRUE DAMAGE to you when I can just get a dead mans plate, get more stats that work at all times and STILL get the same speed with an added bonus auto damage in lieu of my reducing adc damage by 12....

What if the assassins/mages etc can one shot your adc! I still hear you say In which case Ill say: Ill buy a locket for the SAME price of 2200 which will complement my dead mans plates armor with more armor and lots of magic resist nicely, put its extra 175 health to good use as a shield and be able to protect all my team who are present.

Shouldn't I just go back to playing full tank support without dedicated items? Wouldn't you?