That is a very nice proposition. I'm going to read the basics of each 4.0 class before asking questions.
Independently from healing, I think we can compare mastery and agility for Druid in term of damage reduction. For example, if we use T11 premade given by Satorri, and add 716 budget points, it gives :
- 4 points of mastery
- 3 points of dodge
- 2,2 points of critic. (which I modified to 2,5)
- 1450 points of AP. (which is subject to error)
Concerning bear critic, it's subject to error as I'm not sure if non periodical critics will be used. In fact I have used a 45% critic base as my simulator is simply based on a 1 strike/second for the bear, (So it is approximate) which is what it seems 4,x pre-cataclysm bears seem to get. Many simplifications I admit.
Now, we must know how Savage defence work. It is based on druid attack for having a bubble for the next boss melee swing. So value of the amount absorbed depends of both attack speed from boss and Bear. Also note that increasing dodge is equivalent in increasing boss attack delay.*
I decided to simulate a 2 and a 1 seconds melee swing for the boss during 15000 hours of simulation (error is +-1 but I rounded anyway), it gives :
1s : 2090 damage absorbed by second on average with 4 more points in mastery rating.
1s : 2280 absorbed by second on average with 716 in agility
1s : 1890 with no adjustment
2s : 1740 absorbed by second on average with 4 more points in mastery rating.
2s 1880 absorbed by second on average with 716 in agility
2s 1570 with no adjustment
If we make a simple linear regression to estimate ratio between mastery and agility, we have :
1 point of agility = 1,8-1,9 points of mastery.
Now, if we consider Spike damage, It is similar which is not surprising as Agility and mastery have finally the same role.
*I took 1s attack speed from the boss to evaluate the influence of dodge on savage defence bubble.
1889 absorbed with (28% dodge before DR) and 1884 absorbed with (38% dodge before DR), error being +-1. It looks like dodge doesn't have a great influence on savage defence.