When gearing a prot warrior it’s important to understand how much Haste you really need.
When going into just about any pack you wanna use Shield Block
3 times, depending on your haste there might be a small gap of downtime without shield block between the 2nd and 3rd use, but this doesn’t really matter as you can just either stun the pack or step out for half a second until its ready. When the 3rd charge has finished you want to use Last Stand
(With the Bolster
talent selected), and after the 15 seconds of last stand you should be close to having 2 charges of shield block ready or if you have around 20% haste they will both be ready.
Now the thing is, even if you were to play with only 10% haste, the only thing this really changes is that you have to wait 3 seconds for your 3rd shield block charge AFTER last stand to be ready which really doesn’t matter in dungeons because stepping out of the pack for a short amount of time to recharge or making sure something like demo shout is covering that downtime it really puts haste way below mastery.
With 3x Shield Block
> Last Stand
> 3x Shield Block
you essentially have 51 seconds of block uptime that requires basically no haste at all to pull off.
During Tyrannical weeks Haste definitely gets more value, but it all comes down to fight length. You really just need experience to see how long bosses live with your current setup and how long trash packs live. Generally on trash since you can get 51 seconds of block without any haste, haste is pretty worthless on trash, but some dungeons have very scary bosses that you do need to be prepared for and having enough haste can be essential to you living or not in some fights.
On bosses it is by far way more important to have a higher uptime on your block rather than focusing on your block to be more powerful.
Good examples here would be Yazma
in Atal’Dazar, Soulbound Goliath
in Waycrest Manor and King Dazar
in King’s Rest. These bosses can do a lot of damage to tanks and they all have “tank busters” which is a big hit on the tank and it is CRUCIAL that you have block up when these hit, on high tyrannical you are very likely to get 1-shot by these mechanics if you don’t have block up.
As a conclusion, I find it very rare that I need more haste in dungeons, and just playing smart with Shield Wall
and Demoralizing Shout
to cover downtimes of block, it allows me to get away with stacking mastery.