You cannot put a price tag on stats so easily, especially not at the start of a new tier. Tanking is not a science, despite the work of Theck and others.
If you gearing for the lowest and smoothest damage intake possible is what your raid needs, you gotta do it. Your lower damage could be compensated by a disc priest allowed to Atonement heal because you won't die so suddenly.
If you going all out in crit is what's needed, you gotta do it. Your healers might be able to keep you up anyways and your Riposte-independent dps could be very useful.
Point I'm making is, we can only give general guidelines like "if you stack this and that stat, it will have this effect". Use this to tailor your gear to your raid's needs and perhaps your own fun. How tanks play is very dependent on the raid group and the context of your own guild's situation will be the largest deciding factor.