This question is essentially about the relative value of stamina vs mastery and so, while it might be easy to ask, it is rather hard to answer. It's been endlessly debated here, with proponents on both sides and no consensus. Most agree that the principle is to get enough stamina for the encounter then stack mastery (until block capped) but what is enough stamina is unclear (and few can get block capped without straining hard).
That said, my impression is that even some of those keen on stamina on this board also use the Baradin Hold mastery/resist trinket because of the on-use function. It is a nice all rounder because the mastery helps with melee damage while the resist can help with some magic damage that mastery would not help with. I use it and a stamina trinket for my sadly limited raiding; from the posts of more experienced raiders here, it seems the most common set up.
I would go all mastery if it could get me to block cap, but I am still a few points shy of that gemming mainly for mastery and that gemming strategy has left me with relatively low HPs. Consequently, I use a stamina trinket to bulk me up.
EDIT: If you want to know what bosses mastery is good/bad for relative to stamina, a user is trying to start a discussion on that issue here:
http://maintankadin.failsafedesign.com/ ... =viewtopic