Tanking Metagems: Armor vs. Block

[Everest]

Looking at the tanking metagems in Cata, we can choose either

Austere Shadowspirit Diamond - 81 stamina, 2% Armor
Requirement: 2xYellow
or

Eternal Shadowspirit Diamond - 81 stamina, 5% Shield Block Value
Requirement: 3xBlue


In Wrath the Armor one was obviously the best, since the block value one had defense (has dodge now).

But with the changes to block in 4.0, i am not entirely sure of what to pick between these two gems.

The block value one obviously has an advantage with the requirements beeing a non issue, but i am not so sure about the effect 5% more blockvalue will have on mitigation.

Right now i am leaning to the block one, but anyone got some ideas on the issue?

Mostly asking if the new mechanics for block are good enough to make the 5% block better than the 2% armor.

[Martie]

Let's see. 2% more armor always works, block or no block. 5% block only functions on a successful block. Since the damage resistance values of the two look to be similar, it'll depend on how much mastery you have.

[Everest]

Been thinking a bit more.

5% shield block value could mean 2 things.

It could either be a 5% put on top of the 30% block we already have. Adding up to 35% block

Or it could mean you increase the 30% by 5%. Adding up to 31.5% block.

Anyone lucky enough to be on cataclysm beta and can test this?

[Rigormårten]

I cannot say for cata beta (sorry) but currently on live, I use the gem with 21 dodge and 1% block.
(I know it's sub-optimal, but it was the only one available from AH at the time and I cant be arsed to replace it since I'm closing in on buying the T10 helmet)

And on my character sheet it increases amount blocked to 31% (I assume 62% on critical)
However it still says 30% in my armory page.

Hope this is helpful information, apologies if not.

[Everest]

Seems like we can assume it will be 35% blocked in with the cataclysm meta gem then.

Think it will be the gem i go for then. Having to take 2 yellow gems for the armor meta is pretty crap,
and the extra 5% block should do nicely, provided mastery becomes a worthwile stat to mass.

[Andenthal]

Who cares about the meta reqs? 5% damage absorption on a block outscales 2% armor as you approach block cap (it actually passes it quite a bit before then on "average damage taken" it's just not gauranteed). That in and of itself will make this a kick ass gem. (assuming it's a 35% block of course)
If it also makes crit blocks 70% - game over man!

Zarko pointed out Warriors are likely to hit block cap in T12, while Paladins can likely do it late T11.

[vorbis]

It could either be a 5% put on top of the 30% block we already have. Adding up to 35% block

Or it could mean you increase the 30% by 5%. Adding up to 31.5% block.

Anyone lucky enough to be on cataclysm beta and can test this?

I tried this meta-gem out on Beta last week with an 85 pre-made. It appeared to behave according to the second explanation. My block went from 30% to 31% in the character sheet.

[TomHuxley]

It looks like the block meta will end up being better as mastery scales. One thing that should change a bit in Cataclysm is that with bosses taking longer to kill you and healer mana limits a larger problem than throughput, average mitigation could matter more on boss fights than the simple "it has to always work in the worst case scenarios" situation of the last couple expansions. How much that matters of course depends on what the final numbers look like...

[Satorri]

This should really be in the beta discussion forum.

Also, I would assume that the "block value" looks a likely candidate for an untouched hold-over from the redesign of systems. I wouldn't be surprised to see it turn into something else.

If that is not the case, 2% more armor would represent a tiny but every present reduction in physical damage taken, while the increased block amount would scale with your chance to block very heavily to be an occasional, but larger cut. Assuming this does carry over, it will be pretty easy to figure out the larger overall value, and then it will just be a matter of how you want to take less damage.