Don't double post in a slow moving thread such as this, just edit your previous. I merged them for you.
Wanted to confirm your findings for avoidance mitigation - I was unable to find these figures earlier so I recently determined them in game and with a little solver action. All figures I determined match your findings here.
I notice however that in your cata stats you still have a line for Block Rating - unless I'm mistaken, there is no more block rating in Cata.
As far as we know, there is no DR for block obtained via warrior mastery, yes? What about mastery effects in general? I'm headed off to test this anyways, so I might be back later to just answer my own question
Definitely no mastery DR for block or crit block, either in tool tip or in actual in game performance that I was able to measure.
This next bit might belong in warrior forums only as it's particular to their mastery mechanics, but I'll include here for interest anyways.
I went ahead and put together an interesting table (level 80 values only, sorry), for the pure damage avoidance/mitigation crossover points for parry/dodge and block/mastery.
Generally speaking, parry and dodge are superior to warrior mastery rating in terms of providing more long term damage avoidance. At high levels, however, there is definitely a crossover point. Parry and Dodge ratings become equivlent to mastery rating at around the 1000-1100 rating mark. At this point, roughly 83 rating of parry or dodge is equivlent in terms of strict damage reduction to 83 mastery rating. Obviously, mastery rating is nice because it helps smooth out the incoming damage stream more than parry/dodge, but that's definitely more of a class specific discussion I won't get into.
If we take the cata beta values for mastery (2.5% crit block / point mastery versus live value of 1.25), the crossover point occurs much earlier, between about 750-800, where 72 parry/dodge rating is equivlent to 72 mastery rating.