Pre-kara avoidance (dodge/defense/parry) is pretty darn good, until you get so much that your rage becomes gimped.
But in real world choices, so far as an MT going from tanking blues to Kara purpz, it was pretty easy to over stack dodge rating, especially when you keep reading that block rating is the devil. And this new tank is going to find his threat per second suffers in certain fights with too much dodge! What is he to do? At that stage, it's hard to get enough EH together to compensate without something like the tankatronic, furies deck, or the breastplate of kings.