I have updated my spreadsheet I was using to calculate Holy/Disc stat weights on AskMrRobot.https://docs.google.com/spreadsheet/ccc ... Mmc#gid=16
Obviously it is still going to be a little raw... as I don't have all the information yet. I calculated some theoretical stat weights that should work pretty well for now, and then I will revise them and add multiple presets to the site based on actual raid parse information.
It's hard to use the spreadsheet... but, basically it works backwards from what happens in a fight. Enter in all the spells, hits, ticks, mana gains, etc. and then it tells you which stats will increase your HPM (Healing per Mana or Total Output) and HPS (Healing per Second) the most.
Given the data you input into it, the weights it spits out will necessarily increase your performance if you do the exact same thing the next fight (i.e., it is internally consistent). The "subjective" element to the weights is whether to care more about HPM or HPS. Both are important at different times. Right now I just average the two... which may or may not be the best solution.
In Cata, I sort of just followed the trends for stat weights, and had my calculated ones on the site as an alternate. In MoP, I am going with my calculated weights as the defaults, because I feel confident in the technique being used. What I'd like to get the community involved in is deciding what sort of spell breakdown is most realistic/optimal for Level 90 raiding. I could easily see different weights for 10/25 and AoE/Tank Healing scenarios.
Here are the priorities I am going to suggest (the actual numbers are on the "Theoretical Stat Weights" tab in the spreadsheet, in bold):
Spirit > Haste (12.5%) > Crit > Haste > Mastery
Spirit > Haste > Crit > Mastery
Some interesting notes:
1.) For Holy, the choice of spells has much less impact on stat weights than Disc.
2.) Mastery is pretty weak for both specs, although better for Disc - especially if you can use a substantial amount of PW:Shield. I'm not really recommending any mastery stacking at this point.
3.) I think we'll need to stack Spirit at least for the first tier of content, so I'm weighting it high.
4.) Glyph of Renew. If you are going Chakra:Serenity, I think this will be good. If you are using it more for raid healing, you get better healing by going non-glyphed and having 5 ticks/cast. Getting 4 ticks/cast with the Glyph might be tough to achieve if you are stacking spirit, and it does the same amount of total healing.
1.) Anyone know how Halo works? Right now the spreadsheet just assumes max heal on everyone... which is ridiculous and kinda creates some silly results. I'll diminish it by a realistic factor - probably need some actual raid parses to do that, though.
2.) Getting 12.5% Haste is extremely valuable if you are going to use Renew to any significant degree. But, as Disc, you could just cast Renew after PW:Shield with Borrowed Time up and always get the extra ticks. I think it may be realistic to consider using this casting pattern and do away with the Haste "soft cap". Getting the second tick of Renew isn't really going to work in Tier 14 unless you stack a lot of Haste, even with Borrowed Time. As Holy, I think Haste is the best stat, so I don't really worry about the soft cap since I'm stacking haste anyway.