It is, the OP's profile is more of a dream profile.

I was under the impression that separate haste effects in 1.12 will stack multiplicatively rather than additively.

Yep, so instead of 1 + 0.01 + 0.01 + 0.01 = 1.03 (+ 0.30 = 1.33 with flurry up), it'll instead be 1 * 1.01 * 1.01 * 1.01 = 1.0303 ( * 1.30 = 1.339 with flurry up).

Golly, a whole 'nother 1% attack speed (almost) when you have all three haste enchants and flurry up! So yeah, they may stack multiplicatively now, but it doesn't change much when you're talking about such small numbers. Without flurry there's only 0.03% speed difference between the two ways of stacking the effect, which probably doesn't even make it past rounding. When you DO have a larger multiplier (such as flurry) however, the effect is much more noticeable... close to another 1% haste.

The nice thing is that this is a nerf to slowing effects and a buff to haste effects (similarly a buff to threat-increasing modifiers and a nerf to threat-reducing modifiers), which makes for some interesting effects, especially considering horde don't generally use TA much.

Haste enchants have always stacked multiplicatively.

So wouldn't haste actually be a lot better than the math would suggest, once you factor in human error and response times?

Yes.

Edit:
To elaborate, the 16 ap from the +8 str voracity libram gives you damage on your instant attacks, which has to be made up by the increased white damage from 1% haste. The calculations I did for the break-even points assumed instantaneous usage of BT/MS/WW; any amount of slowdown on these (because of lag, or human error, or lack of rage because it's being spent on TC/Demo shout/sunder whatever) reduces the benefit you get from the extra ap on the specials, whereas haste is always benefiting you as long as you're swinging at the mob.

I'm gonna assume that's the same for Orcs using two axes? I've recently begun looking into Fury dualwield, wielding Crul and Doom's Edge, and I got a pair of Edgemaster's just in case.

Will I win or lose if I swap them in for my GoA?

Sorry for the derailment, but I saw an opening here.

Since it works multiplicatively, how about adding a Iron Counterweight enchant on the 2H (3% faster attack speed) ending up with 1,0612 ( or 1,38 with flurry)?

Crusader is just too good. Though, the numbers I'm looking at, 5% haste would be close with tons of buffs, and 6% would be slightly better under the same conditions.

Please elaborate Thorb. I don't see how any part of TF's proc is counted as white damage, hence generating more rage.

Maybe he just means it will proc more often? ^^

For orcs/humans GoA > Edgemasters > Flameguards
For daggers Core Leather Gloves > Edgemasters > GoA > Flameguards
For swords with Maladath offhand GoA = Edgemasters > Flameguards
For everything else Edgemasters > GoA > Flameguards

I ran the spreadsheet + the mods I recommended making. The key difference is execute spam speed with weapons > 1.9 speed. If your flurried speed is > 1.5 speed, you are not going to be executing every 1.5 seconds, not even counting misses/dodges/glancings/etc. Since execute efficiency depends on how much rage is used, the faster you execute the better. It is just as efficient when it comes to execute damage to generate 10 rage every 1.5s as 50 rage every 3s. Haste not only increases your rage generation by 1%, it increases the speed by 1% as well unless you are using iblis/widow or some other fast/fast combination. The calculation I used just uses your average swing speed as the execute cooldown. This isnt 100% accurate due to misses/etc and maybe with different speed weapons your offhand can hit hard to occasionally generate the 10 rage you need but its closer than saying you are executing every 1.5s with dual deathbringers.

+8 strength doesn't help with the proc damage of Thunderfury (the only thing about the weapon worthwhile for DPS), while +1% haste increases the amount of procs by increasing the amount of swings. +15 Agi to gloves versus +1% haste though is still in favor of Agility though, even with Thunderfury.

1%haste is more dps than 15 agi for thunderfury. That was the only weapon that was true for in the spreadsheet.
Edit: depending on buffs.