Update 6: Updated for Mists of Pandaria! Enjoy!
The question about the haste breakpoints for Restoration gets asked a lot. Occasionally someone would put up a list of breakpoints that has some errors in the values (probably due to rounding errors). Also there are questions about Dark Intent’s effect. So I thought I’d put up a list of the breakpoints here, and at the same time explain the theorycraft and maths behind it. You can visit the spreadsheet on Google Docs where you can view the formulas, or just view the summary here:
[iframe https://spreadsheets.google.com/pub?hl=en&hl=en&key=0AuwcTdFIcJZydHZlY09wQTQ3UUxKZVJWa04yQ1ZsTHc&single=true&gid=1&range=A2%3AH34&output=html 514 700]
The first extra tick for any HoT or DoT is granted when Haste% is half of 1/base_ticks, and subsequent extra ticks come at intervals of 1/base_ticks. For example, Rejuvenation has 4 base ticks, therefore extra ticks will come at 12.5%, 37.5% and 62.5%. Lifebloom has 10 base ticks, therefore extra ticks will come at 5%, 15%, 25%, etc.
Haste bonuses from 5% Raid Haste Buff (e.g. Mind Quickening) and 3% from Dark Intent stack multiplicatively. In the case of Rejuvenation, 12.5% haste is required for the first tick, but with 5% Haste Buff, 7.14% haste is required instead of the expected 7.5%, as 1.0714 x 1.05 = 1.125, and with Dark Intent you only need 4.02% Haste, as 1.0402 x 1.03 x 1.05 = 1.125.
So what are the haste breakpoints to target? In my opinion, you can generally expect to have the Raid Haste buff in a Raid environment, in which case 916 Haste Rating is the most important breakpoint to target. This gives you a whooping 25% increase in the total healing done by each Rejuvenation cast.
The value of 12th tick of Lifebloom (obtained at 1221 Haste Rating) depends on your healing style. If you are continually refreshing Lifebloom before it drops, then you won’t see the value of the extra ticks. In this scenario, Lifebloom actually benefits perfectly from Haste value in between the extra ticks. The other scenario is where you are letting Lifebloom bloom, which is not a popular playstyle, in which case you get the full effects of the extra tick. This breakpoint gives 9.1% more healing, so it’s not really something that impressive.
The 4th Regrowth tick (obtained at 1422 Haste Rating) is not very valuable at all, since you should generally be limiting your Regrowth casts as much as possible. While it is true that the 4th tick of Regrowth gives a 33.3% (repeating of course) increase to the number of ticks, over half of Regrowth’s healing comes from the direct heal.
At 2005 Haste Rating comes the 9th tick of Wild Growth, and with the huge buff to Wild Growth in 4.0.6, you should be looking to use Wild Growth as much as you can assuming the raid needs it. This makes the 2005 Haste Rating extremely good (unless you are always being assigned to pure MT healing). You should generally try to reach this breakpoint if it is possible to reach there without sacrificing significant amount of Intellect.
UPDATE 1: It has been determined using my Resto Druid Spreadsheet (using Mixed MT + Raid healing model) that it is definitely worth going for the 2005 Haste Breakpoint (for 9th tick of Wild Growth), sacrificing 1089 Mastery Rating to increase Haste Rating from 916 to 2005.
UPDATE 2: Updated chart with my findings about the rounding behavior performed on the server side, which apparently is different from the rounding behavior on the client side (character sheet).
UPDATE 3: Efflorescence in 4.1 will have base 7 ticks (same as Wild Growth), so will follow the same the same Haste Rating requirements as Wild Growth
UPDATE 4: Fixed rounding behavior again, thanks to Erdluf. Also, by popular demand, I’ve included breakpoints for our feathered friends. Also included a column for Nature’s Gra
spce + Raid Buff (and removed the column for Dark Intent on its own).
Update 5: Added breakpoints for Tranquility. Same number of ticks as Rejuvenation, but due to Rounding method used and the different interval between ticks, the break-points are slightly different.