Resto Shaman Mastery, YAY or NAY?

So i have just come back from an almost 4 month break from World of Warcraft, Only to find that various parts of what i expected in Cataclysm have already hit, Name Mastery.

Now i understand that in order to obtain Mastery, I would need to reforge some of my gear to obtain Mastery stat, And that each point of mastery gives me a 2.5% addition to my direct healing spells up to a total of 20% on targets with lower HP.(if this is wrong please inform me)

I am utterly confused on the effectiveness and utility of the Mastery for Resto Shaman's at this point in time, But i have been told it ideally comes down to my gear level and factors such as going OOM on fights or not.


Unfortunately i just moved to a new server due to various reasons and Armory isn't showing my character but my stats look something like this:

34,000 HP
38,000 Mana
3,900 +Healing
35% Crit
1350 Haste
867 MP5 (660 While Casting)

I never run out of mana during boss fights and on non Heroic Encounters, PUGs, and 5-Mans i merely spam Chain Heal which doesn't exactly put large holes into a Shamans Mana Pool.


Would it be productive for me to take up Mastery or should i just carry on life as normal?


If there is any information i have left out or that you feel is relative i have not included aswell as any questions, Please feel free to ask and i will answer them as promptly as possible.


Thanks

Well it all depends on ur playstyle. At the moment i wouldnt say mastery is crucial because when Cataclysm comes out we will be getting gear with 120+ mastery on it. so i wouldnt say its necessary right now at this time. But say u want to try it as i currently am with pretty close to the same stats as you and as a shammy I really loved my haste and the little cast time to cast healing surge so what I did was replaced some of my Crit With mastery. I just really havent noticed a diffrence all too much in healing numbers tho. But maybe you can try and tell me diffrent.

I would go on life as normal. As far as I understand the mastery it heals for more the lower percentage health of your target. With the way Wrath is, you normally can't afford to let someone get too low without risking them dying.

If anything I would take the time to get used to the changes in spells like healing surge, healing wave, greater healing wave and such and wait until Cata to deal with mastery.