For 10mans, generally you're not going to function as a bubblebot like you would in a typical 25. So crit/haste gear is optimal.
Good decision on the mace, use Shriveled Heart for the extra haste, and you should probably aim for haste on gear unless you're mostly raid healing. In which case, it doesn't really matter what stats are on there besides spellpower (and possibly intellect) when you're a bubblebot.
It's a judgement call, for me personally - mostly reliant on bubbles go with T10 4-piece, mostly reliant on spells with cast times go with the haste offpieces.
Some other stuff I would change in your armory:
- Use the Insightful Eartsiege meta, which is grossly overbudgeted on the mana proc. The extra mana will give you enough leeway to drop the intellect gems.
- Lose the +10 stats gem, it does nothing for you.
- Don't gem crit. It's a nice stat, but not as good as others like spellpower, haste, or intellect.
The healing team in our 10 mans, is holy pala, resto druid and me disc. So im kinda the middleman filling gaps. Mostly preventing damage with grace, renewed hope and shield. Helping on tank healing helping on raid healing. Thats why i have been holy for so long. But when we started sindragosa and the lk i tried out disc, and i fell i love with it. The lk fight is so amasing, trying to time shield with infest so rapture procs. Helping the holy pala keeping the tanks alive during soulreaper etc. There i feel so usefull as i have never done as holy.
But ye since i spend most of my time Prayer of Mending ´ing, bubbling, penance, and a lesser amount of time with flash heal, greater heal and prayer of healing. This is the reason i was thinking critt not so much haste.
So i suppose T10 4 set bonus regem abit and get a good mix of haste/critt/int is a good way to go. Maybe even focus abit more on pure sp gems insted of my Sp/haste/critt.
You definitely want to aim for 4pT10, unless you're almost exclusively tank healing, which you really shouldn't be. As such, your best choices to off-set are probably either Chest or Legs, both of which easily obtainable Haste/Crit options; personally, I'd aim for the Chest with either the Shadow T10 or Emblem versions because I'd value the Haste on the legs more than the Crit on the Chest.
Definitely don't be gemming Crit. If you need to match a yellow socket, you should use either SP/Int or SP/Haste, but you really ought to not need the Int, and in the vast majority of cases, straight SP will benefit you more than a socket bonus. Don't use a prismatic gem, it's just not worth it; if you have to match a Blue socket, SP/Spirit is going to be a better option. For you meta, consider IED, if you trade out all your gems for pure throughput, your cloak enchant to Lightweave, and still don't need the regen, then ESD is better, but not by very much since you have to use Blue gems to activate it. Speaking of which, if you ARE going to match a blue socket for the meta, the one in your Hat is definitely one you want to use since it's a 9 SP bonus without having to match any other Blues/Yellows to get it.
ETA: Didn't see your post when I posted. With that team, your tank healing is pretty much limited to PoM and an occassional Penance or PWS, so definitely aim for 4pT10. Also, with more focus on the raid, definitely consider dropping your FH glyph for something like PoH.
yuor gear is pretty optimal at the moment.. for 10 man there might be minor adjustments you can make but you shuold be diong fine. You should go for the 4piece t10, theres no reason not taking it anyways, and no reason that you should not be doing 25 man's either :P
and your gemming is pretty proper, full SP for disc is the way to go imo.