The default profile for Affliction Warlocks has
Essence of Terror as one of the trinkets. When I test, I always use
Relic of Yu'lon, so I don't get a haste proc that messes up the simulation.
The stat scaling feature in SimC should not be blindly trusted. SimC has a tendency to put a lot of stress on reaching haste caps, but I'm not certain that for a player, it would always make that much of a difference. Let me show you a few example.
The T14 Heroic profile has a secondary stat budget of 2008+6590+8152 = 16750. I'll set Critical Strike Rating from gear to be at 2,000 and I'll make Haste Rating and Mastery Rating vary.
Let's first see how much impact on the DPS the various breakpoints have. For this, I check the DPS at 1 Haste Rating below the breakpoint and then again at the breakpoint.
Unstable Affliction +2 ticks (6637 Haste Rating, 8113 Mastery Rating): +100 DPS
Unstable Affliction +4 ticks with
Dark Soul: Misery (4198 Haste Rating, 10552 Mastery Rating): +314 DPS
Unstable Affliction +5 ticks with
Dark Soul: Misery (8647 Haste Rating, 6103 Mastery Rating): -64 DPS
Agony +2 ticks (3043 Haste Rating, 11707 Mastery Rating): -200 DPS
Agony +3 ticks (6400 Haste Rating, 8350 Mastery Rating): +268 DPS
Agony +4 ticks (9778 Haste Rating, 4972 Mastery Rating): +284 DPS
Agony +6 ticks with
Dark Soul: Misery (2904 Haste Rating, 11846 Mastery Rating): -153 DPS
Agony +7 ticks with
Dark Soul: Misery (5494 Haste Rating, 9256 Mastery Rating): +22 DPS
Agony +8 ticks with
Dark Soul: Misery (8107 Haste Rating, 6643 Mastery Rating): -47 DPS
Corruption +2 ticks (8085 Haste Rating, 6665 Mastery Rating): -21 DPS
Corruption +4 ticks with
Dark Soul: Misery (6805 Haste Rating, 7945 Mastery Rating): +73 DPS
As you can see, reaching a breakpoint is not always beneficial to your DPS and even when it is, you will hardly feel the difference. That said, these are simulation results, so you shouldn't take them at face value.
Now, I'm going to try and find the best DPS value by keeping Critical Strike Rating at 2000 and making Haste Rating and Mastery Rating vary, but in such a way that Mastery Rating + Haste Rating always equals to 14750 (so I remain within the stat budget of the T14 Heroic profile).
- 2000 Haste Rating, 12750 Mastery Rating: 124912.2 DPS
- 2250 Haste Rating, 12500 Mastery Rating: 124838.9 DPS
- 2500 Haste Rating, 12250 Mastery Rating: 124990.4 DPS
- 2750 Haste Rating, 12000 Mastery Rating: 124869.5 DPS
- 3000 Haste Rating, 11750 Mastery Rating: 124823.4 DPS
- 3250 Haste Rating, 11500 Mastery Rating: 124841.0 DPS
- 3500 Haste Rating, 11250 Mastery Rating: 125179.8 DPS
- 3750 Haste Rating, 11000 Mastery Rating: 125471.4 DPS
- 4000 Haste Rating, 10750 Mastery Rating: 125713.9 DPS
- 4250 Haste Rating, 10500 Mastery Rating: 126439.0 DPS
- 4500 Haste Rating, 10250 Mastery Rating: 126415.9 DPS
- 4750 Haste Rating, 10000 Mastery Rating: 126544.0 DPS
- 5000 Haste Rating, 9750 Mastery Rating: 126686.6 DPS
- 5250 Haste Rating, 9500 Mastery Rating: 126716.7 DPS
- 5500 Haste Rating, 9250 Mastery Rating: 126795.8 DPS
- 5750 Haste Rating, 9000 Mastery Rating: 126891.2 DPS
- 6000 Haste Rating, 8750 Mastery Rating: 126811.2 DPS
- 6250 Haste Rating, 8500 Mastery Rating: 126716.5 DPS
- 6500 Haste Rating, 8250 Mastery Rating: 126990.6 DPS
- 6750 Haste Rating, 8000 Mastery Rating: 127103.4 DPS
- 7000 Haste Rating, 7750 Mastery Rating: 127159.5 DPS
- 7250 Haste Rating, 7500 Mastery Rating: 127198.1 DPS
- 7500 Haste Rating, 7250 Mastery Rating: 127100.9 DPS
- 7750 Haste Rating, 7000 Mastery Rating: 127620.5 DPS
- 8000 Haste Rating, 6750 Mastery Rating: 127503.3 DPS
- 8250 Haste Rating, 6500 Mastery Rating: 127386.0 DPS
- 8500 Haste Rating, 6250 Mastery Rating: 127293.5 DPS
- 8750 Haste Rating, 6000 Mastery Rating: 127269.5 DPS
- 9000 Haste Rating, 5750 Mastery Rating: 127245.3 DPS
- 9250 Haste Rating, 5500 Mastery Rating: 127233.2 DPS
- 9500 Haste Rating, 5250 Mastery Rating: 127375.4 DPS
- 9750 Haste Rating, 5000 Mastery Rating: 127175.5 DPS
- 10000 Haste Rating, 4750 Mastery Rating: 127483.7 DPS
- 10250 Haste Rating, 4500 Mastery Rating: 127265.7 DPS
- 10500 Haste Rating, 4250 Mastery Rating: 127385.2 DPS
- 10750 Haste Rating, 4000 Mastery Rating: 126826.1 DPS
- 11000 Haste Rating, 3750 Mastery Rating: 126783.2 DPS
- 11250 Haste Rating, 3500 Mastery Rating: 126588.3 DPS
- 11500 Haste Rating, 3250 Mastery Rating: 126522.7 DPS
- 11750 Haste Rating, 3000 Mastery Rating: 126383.0 DPS
- 12000 Haste Rating, 2750 Mastery Rating: 126232.1 DPS
- 12250 Haste Rating, 2500 Mastery Rating: 126212.3 DPS
- 12500 Haste Rating, 2250 Mastery Rating: 126019.9 DPS
- 12750 Haste Rating, 2000 Mastery Rating: 125925.1 DPS
As you can see, the best results seem to be when Haste Rating and Mastery Rating are properly balanced. These are still simulation results and Simulation Craft does a very good job at playing properly. Whether a real player can properly benefit from their increased casting speed and DoT ticking speed remains to be seen, whereas Mastery is a direct increase to damage done that is not affected by skill. This is why we advise Mastery before Haste, because we're unsure whether or not the Haste results are applicable to real life.
Simulations were done with Simulation Craft. I compiled it this morning with the latest changes on the SVN.