Yeah seems like a perk people like. But as I stated in every COD game knives and grenades have killed me anyway, so the way I look at it, you can't avoid every type of death and it's not like MW2 Noobtubes are in Black Ops...So I'd rather change mine, teammates, enemy care packages with Hardline Pro or rush without worrying about Air Support killing me when you face those teams that run Spy Plane all game, so for those times I use Ghost Pro. I love the Flak Jacket users though, gives me an easier target in the Huey or Hind.
I'd argue Tatical Mask Pro could be as important, since it shows you where enemies are when you flash them and keeps you from being flashed or concussed.