But in the end, the analysis is not that clean.
While Spell Power increases Block, when talented it also increases Dodge and Parry. Typically, the Spell Power of 2-handers is far greater than a 1-hander and shield (huge itemization problem, IMO). By far greater, I am talking about typically DOUBLE the Spell Power from a 2-hander. Once you spec 3 points into Devout Deflection, the bonuses your get to avoidance seems to offset the loss from Block (+60% to Dodge, +90% to Parry).
I'm not sure anyone has really done a parse of this debate though. I also think that a lot of the early discussions were at a time when Devout Deflection gave a higher mitigation percentage than what is currently listed.
Personally, I notice that I suffer from a LOT of burst damage with a 2-hander so I abandoned 2-handed tanking. However, now that my curiosity is piqued, I may spec 2-handed tanking and give it a whirl to compare.
Connect With Us