Cross post from http://eu.battle.net/wow/en/forum/topic/5967267323#1
Before we start I want to say that I did not count in Healing Touch being able to crit. The reason for this is that I don't a healing should rely on their heals criting. Healing should be steady and reliable. But when healing Touch crit, it will always be better than Regrowth.
If I have done any mistakes please let me know so I can edit the post accordingly.
Regrowth+Glyph vs Healing Touch
***Spells***
[Healing Touch] Level 90
28.9% of base mana 40 yd range
2.5 sec cast
Requires level 26
Heals a friendly target for 18460 to 21800 (+ 186% of SpellPower).
[Regrowth] Level 90
29.7% of base mana 40 yd range
1.5 sec cast
Requires Druid (Restoration)
Requires level 18
Heals a friendly target for 9813 to 10954 (+ 95.8% of SpellPower)
Regrowth has a 60% increased chance for a critical effect.
[Glyph of Regrowth]
Major Glyph
Classes: Druid
Requires Level 25
Item Level 25
Increases the critical strike chance of your Regrowth by 40%, but removes the periodic component of the spell.
***Healing***
Regrowth
0.958 = 95.8%
(9813+(Spellpower*0.958))*2 = X
(10954+(Spellpower*0.958))*2 = X
Average:
10383.5 + (Spellpower*0.958) * 2 = X
Healing Touch
1.86 = 186%
18460+(Spellpower*1.86) = Y
21800+(Spellpower*1.86) = Y
Average:
20130 + (Spellpower*1.86) = Y
Q. Can Y become bigger than X?
A. No. The reason is, with Glyph of Regrowth, Regrowth it has a 100% chanse to crit.
Giving Regrowth 0.958*2 = 1.916 = 191.6% vs 186% from Healing Touch
For each Spellpower you get regrowth will pull more ahead.
***Mana***
Regrowth = 29.7% of base mana
Healing Touch = 28.9% of base mana
28.9/100*29.7 = 8.5833
Regrowth cost 8.5833% more mana than Regrowth.
***Healing per Mana***
Q. When does Regrowth become more cost efficient than Healing Touch?
A. When Regrowth heal more than 8.5833% then Healing Touch.
Q. When does Regrowth heal more than 8.5833% then Healing Touch?
A.
1.916-1.86 = 0.056
For each Spellpower Regrowth heal 0.056 more than Healing Touch.
Minimum Regrowth heal with 0 Spellpower = 9813*2 = 19626
Minimum Healing Touch with 0 spellpower * 8.5833% = 20044.477
20044.477-19626 = 418.477
418.477/0.056 = 7472.804
Maximum Regrowth heal with 0 Spellpower = 10954*2 = 21908
Maximum Healing Touch with 0 spellpower * 8.5833% = 23671.159
23671.159-21908 = 1763.159
1763.159/0.056 = 31484.982
Average Regrowth heal with 0 Spellpower = 10383.5*2 = 20767
Average Healing Touch with 0 spellpower * 8.5833% = 21857.818
21857.818-20767 = 1090.818
1090.818/0.056 = 19478.893
When you get more than 7'473 Spellpower, the minimum heal off Regrowth is more cost efficient than Healing Touch.
When you get more than 31'485 Spellpower, the maximum heal off Regrowth is more cost efficient than Healing Touch.
When you get more than 19'479 Spellpower, the average heal off Regrowth is more cost efficient than Healing Touch.