Clarification on prot tier bonus'

[Dhiem]

Item - Warrior T17 Protection 2P Bonus - Shield Slam has a 8% chance to automatically cast Shield Block.
Item - Warrior T17 Protection 4P Bonus - While Shield Block is active, your shield block value is increased by 5%.

(the above comes from http://www.mmo-champion.com/content/...-17-Armor-Sets)

Does the tier 2 bonus eat a shield block charge?

Does the shield block value mean you take 5% less damage per block?

[Vongimi]

And how will this affect gladiator stance is what I want to know

[Artorius]

And how will this affect gladiator stance is what I want to know

8% chance to automatically cast shield charge and 5% extra damage on abilities with shield charge.

[Nouway]

Does the tier 2 bonus eat a shield block charge?

No, it procs a free Shield Block/Charge

Does the shield block value mean you take 5% less damage per block?

It will increase your block value from 30% to 35% (therefore your critical block goes to 70%)