[quote:24cc02b636="Baeloc"]

So where Holy Light gets 71% of my healing (2.5 sec cast), Flash of Light (1.5 sec cast) only gets 43% of the bonus.  

Then, when you get to a certain level of +healing/damage.

[/quote:24cc02b636]

I was reading this [url=http://www.wowwiki.com/Formulas:Plus_damage_and_Plus_healing]wowwiki spell damage and healing junk[/url] and it doesn't mention that spell damage or healing becomes less effective as it reaches higher levels.  According to this, it's simply based on spell type (channeled, dot, instant or cast) and then cast time where 3.5 second casts receive 100% of any bonuses and longer and shorter casts are adjusted accordingly.  There's a few exceptions where things like fireball have their extra burn damage after the spell but overall...

Also, it explains how downranking spells gives you a penalty to your +spell/healing so you can't stack +spell and downrank to save mana and get full benefit anymore.

Bae is right though about being gimped by focusing one stat like + healing or damage to the point of lunacy.  Healers with 3000+ healing would be overhealing like crazy and neglecting mana regen, int and stam on their character to reach those levels.

This may be old info, but it's all I found.  If someone could show me that you actually do get diminishing returns on your +spell at certain levels besides the particular cast it was I think all of us would like to know how it really works.

This shows coefficients but it's just what % of +spell/healing you're getting with your different casts...[url=http://www.wowwiki.com/Spell_Damage_Coefficients]Spell Coefficients[/url]