Great guide. The Glyph of Water Shield is linked incorrectly to Ghost Wolf, but very well written and informative.
I have followed the debate between haste and mastery very closely since the start and understand both sides from a 25 man aspect. In 10 mans however, crit has been an extremely important stat as well. In fact, through the final bosses of regular modes I found myself completely reforging to crit for the regen. I am curious how others have found crit holding up in HCs and what order you would place on crit, haste, and mastery from a strictly 10 man point of view?
Interestingly enough I found the case to be the exact opposite in our 10-man with me having the best mana-sustainability while lagging behind in throughput. We were at the time rolling with a Holy Priest, A Holy Paladin and I with all of us close to full 359 gear at the time with me behind farthest behind gearwise having recently switched from Enhancement.
Now I don't want to jump to conclusions but I think that the stat priority you go for will be greatly dependent on how you heal in your raid. Since we had a Holy Paladin he was doing most of the tankhealing with me keeping hots and earth shields up on the tanks while using mostly HW and the occasional CH and/or HR with some time to spend on regen via TC which lead me to prioritize things like mastery and haste. (Especially since we're just starting out hardmodes and mastery is godlike for fights like Halfus and Chimaeron HC)
However I imagine that if you spend alot of time casting HS and chaincasting GHW I imagine crit would prove to be a better route to go since you will likely need the extra regen.
TLDR: My assumption is that the secondary stats you go for will be determined by your own personal style of healing and/or your healer-role.