Based on the unrealistic amount of rating required to GCD cap. May be off by 1-2% due to rounding.

EDIT: Here's some realistic haste caps to aim for.

2 seconds seems to be a common boss swing timer. To get a 2 sec cast time so the boss doesn't hit twice between heals, you need 774 haste.

To get a "nice" rotation of Shock->HL/DL->HL/DL->Some other Instant (repeat), and have the rotation be 6 seconds long you need:

1680 haste.

EDIT2: Ugh, someone's going to misquote me on this and this whole mess is going to blow up into something bigger than it is. Just get enough haste so you don't reflex fail.

In Summary:Can we end this debate now? Here's the math. Now decide for yourself what you PERSONALLY like best.

3491 Haste Rating -

27.247% haste, or 27.247% increase to HPS.

3491 Crit Rating -

19.481% crit or 9.740% increase to HPS and HPM

3491 Mastery Rating -

19.48 Mastery or 24.351% bigger shields or predicted 12.176% increase to HPS and HPM. Assume 1/2 of your shields are wasted.

EDIT: Here's some realistic haste caps to aim for.

2 seconds seems to be a common boss swing timer. To get a 2 sec cast time so the boss doesn't hit twice between heals, you need 774 haste.

To get a "nice" rotation of Shock->HL/DL->HL/DL->Some other Instant (repeat), and have the rotation be 6 seconds long you need:

1680 haste.

EDIT2: Ugh, someone's going to misquote me on this and this whole mess is going to blow up into something bigger than it is. Just get enough haste so you don't reflex fail.

Edited by Lylthe on 12/21/2010 12:58 PM PST