Strength Tanks and You.

[Velox]

I'm more concerned about healers waiting for you to lose half your life to start thinking about casting a cure I.

The amount of DPS a healer can dish out in Cleric Stance massively trumps the DPS of a tank in STR gear. A healer will sometimes allow a tank to drop a bit in health to stay in Cleric Stance longer (this is more true for WHM and AST because they don't have the luxury of free heals from a fairy). A tank with VIT gear can take more hits before he hits the 50% HP mark, allowing for the healer to DPS more, and thus, decreasing the run time significantly.

Basically
A bad STR tank = certain death
A good STR = managable but not optimal
A bad VIT tank = mobs running everywhere but can limp through if DPS back off
A good VIT tank = healer and DPS can go all out and have trash dead before a heal is even needed.