As an introduction, I will say that I am not a MoP player, first timer kinda, but I did spend a few hours on dummies at various gear levels, at two servers, looking at Elusive Brew as a mechanic and so, I will go ahead and write my findings. Do what you want with them.
Describe the bug
How it works:
Dual Wield (2.6s speed):
Generates 1 stack on the odd crits (1st, 3rd, 5th, etc) and 2 stacks on the even crits (2nd, 4th, 6th, etc). The odd/even crits reset when you use your Elusive Brew stacks. This makes it so your generation is 100% predictable and the only thing you have to watch out for is critting when at 12 stacks, going to 13. By that time, you have to use the stacks, or you risk a double crit at the same time, overcapping you.
2H Staff (3.3/3.2s speed):
Generates 2 stacks on the 1st crit, 3 stacks on the next three crits, 2 stacks on the 5th crit. This resets when you use your Elusive Brew stacks. We cannot find out if you generate 2 or 3 stacks on the 6th crit because you cannot hold more than 15 and by the 5th crit, you are at 13, so even if it did, it would be wasted. Have to always use Elusive Brew stacks at 13, or preferably 11. This way, because stacks arent really RNG, you can simply avoid getting 2 stacks of Elusive Brew so often: 2x1 stacks only every 4 crits - 25%, instead of 2x2 every 5 crits - 40% or 2x3 stacks every 6 crits - 50%, respectively.
2H Polearm (3.6s speed):
Generates 2 stacks on 1st crit and 3 stacks on every crit after it. This resets when you use your Elusive Brew stacks. We cannot find out if you generate 2 or 3 stacks on the 6th crit, as we are already at 14 stacks and at that point, we would waste them anyway. This makes it so you always generate 2 stacks of Elusive Brew 20% of the time, 1 every 5 crits.
How it should work
This assumes that another server that wont be named works properly and, based on blizzard mechanics on other things, it probably works properly.
How it should work (based on other server, which has more of a true RNG and not a set in stone proc system):
Dual Wield (2.6s speed):
Generates 1 stack on Offhand crit and 2 stacks on Mainhand crit. This means that over the course of a few minutes, you do end up with the same amount of stacks as on Lotus, but it is more random.
2H Staff (3.3/3.2s speed): On that other server, 2 or 3 stack gen is pretty random, with 2 stacks generating at about 40% of the crits.
2H Polearm (3.6s speed):
I could not find a 3.6s speed polearm, so I tested with a 3.5s on the other server. The proc rate of 2 stacks is at around 5-10%.
To Reproduce
Steps to reproduce the behavior: Hit the dummy
Additional context
Some calcs for the above:
Lotus:
In the span of 2 minutes/120 seconds:
A staff with haste of ~13% and crit of 50% generates a total of 14 (2 stacks) + 63 (3 stacks) stacks. 64,1% uptime on the dodge buff.
A polearm with haste of ~13% and crit of 50% generates a total of 10 (2 stacks) + 66 (3 stacks) stacks. 63,33% uptime on the dodge buff.
Other:
In the span of 2 minutes/120 seconds:
A staff with haste of ~13% and crit of 50% generates a total of 22 (2 stacks) + 51 (3 stacks) stacks. 60,8% uptime on the dodge buff.
A polearm with haste of ~13% and crit of 50% generates a total of 2 (2 stacks) + 78 (3 stacks) stacks. 75% uptime on the dodge buff.
These amounts of stats are available at around BiS HC ToT gear, without the 10% melee haste buff. In other words, Polearms start pulling ahead of staves after you have alreday gotten some SoO gear, realistically, while staves get better much earlier on, maybe even before DW gets crit capped.
Keep in mind that at this test, polearm gen is higher than it should be (1/26 generated 2 stacks instead of 1 or 2/20).
Basic Comparisons
Dual Wield (2.6s speed):
DW is more reliable on Lotus due to being able to 100% predict how many stacks you get next and the only thing you have to watch out for is going to 13 with your current set of white hits. If that happens, you HAVE to use Elusive Brew or risk a dual crit, resulting in a 1 stack loss.
2H Staff (3.3/3.2s speed):
Staves on Lotus are way more powerful than they should be, again, assuming that other place has it right, because you can control the stacks and make it so you only gen 2 stacks every 4 crits by using Elusive Brew at 11 stacks (25% of the time).
2H Polearm (3.6s speed):
Polearms are significantly weaker here due to the insanely higher rate of 2 stack generation for them (20% vs 5% of the time).
Conclusion
The difference between staff and polearm, at the test's gear level, is huge between the 2 servers, due to the base chance of getting 2 stacks for staff vs polearm being different. The randomness allows for this, as you dont end up generating 2 stacks with Polearm every 1st crit after you use Elusive Brew.
Overall, in the span of a fight, the DW here and there are about even. DW here is just more predictable and steady.
Polearms scale the best with Haste (basic stat of BrM Monk) and they should be getting better and better but due to Staves being able to generate almost the same amounts of Elusive Brew, thanks to the predictability of the 2 stack nature, and the fact that for both weapons the 1st crit is always 2 stacks, Staves pull ahead due to their lower base attack speed for almost the entire game.
As an introduction, I will say that I am not a MoP player, first timer kinda, but I did spend a few hours on dummies at various gear levels, at two servers, looking at Elusive Brew as a mechanic and so, I will go ahead and write my findings. Do what you want with them.
Describe the bug
How it works: Dual Wield (2.6s speed): Generates 1 stack on the odd crits (1st, 3rd, 5th, etc) and 2 stacks on the even crits (2nd, 4th, 6th, etc). The odd/even crits reset when you use your Elusive Brew stacks. This makes it so your generation is 100% predictable and the only thing you have to watch out for is critting when at 12 stacks, going to 13. By that time, you have to use the stacks, or you risk a double crit at the same time, overcapping you.
2H Staff (3.3/3.2s speed): Generates 2 stacks on the 1st crit, 3 stacks on the next three crits, 2 stacks on the 5th crit. This resets when you use your Elusive Brew stacks. We cannot find out if you generate 2 or 3 stacks on the 6th crit because you cannot hold more than 15 and by the 5th crit, you are at 13, so even if it did, it would be wasted. Have to always use Elusive Brew stacks at 13, or preferably 11. This way, because stacks arent really RNG, you can simply avoid getting 2 stacks of Elusive Brew so often: 2x1 stacks only every 4 crits - 25%, instead of 2x2 every 5 crits - 40% or 2x3 stacks every 6 crits - 50%, respectively.
2H Polearm (3.6s speed): Generates 2 stacks on 1st crit and 3 stacks on every crit after it. This resets when you use your Elusive Brew stacks. We cannot find out if you generate 2 or 3 stacks on the 6th crit, as we are already at 14 stacks and at that point, we would waste them anyway. This makes it so you always generate 2 stacks of Elusive Brew 20% of the time, 1 every 5 crits.
How it should work
This assumes that another server that wont be named works properly and, based on blizzard mechanics on other things, it probably works properly.
How it should work (based on other server, which has more of a true RNG and not a set in stone proc system): Dual Wield (2.6s speed): Generates 1 stack on Offhand crit and 2 stacks on Mainhand crit. This means that over the course of a few minutes, you do end up with the same amount of stacks as on Lotus, but it is more random.
2H Staff (3.3/3.2s speed): On that other server, 2 or 3 stack gen is pretty random, with 2 stacks generating at about 40% of the crits.
2H Polearm (3.6s speed): I could not find a 3.6s speed polearm, so I tested with a 3.5s on the other server. The proc rate of 2 stacks is at around 5-10%.
To Reproduce
Steps to reproduce the behavior: Hit the dummy
Additional context
Some calcs for the above: Lotus: In the span of 2 minutes/120 seconds: A staff with haste of ~13% and crit of 50% generates a total of 14 (2 stacks) + 63 (3 stacks) stacks. 64,1% uptime on the dodge buff. A polearm with haste of ~13% and crit of 50% generates a total of 10 (2 stacks) + 66 (3 stacks) stacks. 63,33% uptime on the dodge buff. Other: In the span of 2 minutes/120 seconds: A staff with haste of ~13% and crit of 50% generates a total of 22 (2 stacks) + 51 (3 stacks) stacks. 60,8% uptime on the dodge buff. A polearm with haste of ~13% and crit of 50% generates a total of 2 (2 stacks) + 78 (3 stacks) stacks. 75% uptime on the dodge buff.
These amounts of stats are available at around BiS HC ToT gear, without the 10% melee haste buff. In other words, Polearms start pulling ahead of staves after you have alreday gotten some SoO gear, realistically, while staves get better much earlier on, maybe even before DW gets crit capped.
Keep in mind that at this test, polearm gen is higher than it should be (1/26 generated 2 stacks instead of 1 or 2/20).
Basic Comparisons
Dual Wield (2.6s speed): DW is more reliable on Lotus due to being able to 100% predict how many stacks you get next and the only thing you have to watch out for is going to 13 with your current set of white hits. If that happens, you HAVE to use Elusive Brew or risk a dual crit, resulting in a 1 stack loss.
2H Staff (3.3/3.2s speed): Staves on Lotus are way more powerful than they should be, again, assuming that other place has it right, because you can control the stacks and make it so you only gen 2 stacks every 4 crits by using Elusive Brew at 11 stacks (25% of the time).
2H Polearm (3.6s speed): Polearms are significantly weaker here due to the insanely higher rate of 2 stack generation for them (20% vs 5% of the time).
Conclusion
The difference between staff and polearm, at the test's gear level, is huge between the 2 servers, due to the base chance of getting 2 stacks for staff vs polearm being different. The randomness allows for this, as you dont end up generating 2 stacks with Polearm every 1st crit after you use Elusive Brew. Overall, in the span of a fight, the DW here and there are about even. DW here is just more predictable and steady. Polearms scale the best with Haste (basic stat of BrM Monk) and they should be getting better and better but due to Staves being able to generate almost the same amounts of Elusive Brew, thanks to the predictability of the 2 stack nature, and the fact that for both weapons the 1st crit is always 2 stacks, Staves pull ahead due to their lower base attack speed for almost the entire game.
Thanks for your time