On the topic of ele force vs double crusader, it's worth noting that fury's ability damage is all physical damage, and is thus is mitigated by armor, whereas elemental force deals magical damage, which is not mitigated by armor.
Still, in my humble opinion, double crusader is better as +100 or +200 strength is a large boost, which yielded these tooltip numbers on my vet fury warrior's abilities:
Format:
Ability name: Normal numbers, Numbers with +100 str, Numbers with +200 strength
(Baseline (0%), % boost from +100 strength, % boost from +200 strength)
Bloodthirsty: 117, 180, 243
(0%, +53.8%, +107.7%)
Raging Blow: 127, 197, 266
(0%, +55.12%, +109.5%)
Rampage: 302, 469, 636
(0%, +55.3%, +110.6%)
Execute: 211, 327, 443
(0%, +54.98%, 109.6%)
The difference between the boosted numbers can be as large as or larger than a elemental force proc, and even if armor reducing those numbers is taken to account (armor on most classes range can range between 10% to 35%, or 40%+ for tank classes), those differences can add up, especially when one compares the frequency of abilities boosted by crusader to the frequency of double elemental force enchants, which is around 20(1+h) procs per minute (or 10(1+h) ppm with just one ele force enchant weapon), where h is haste as a decimal, like 24% haste is h=.24, for (1+h)=1.24. Due to the mechanics of the RPPM behind ele force (and other MoP+ enchants), it doesn't matter how often one lands attacks, a slow class or a fast class will net approximately the same amount of ele force procs per minute). Furthermore, supposedly Mark of the Hidden Satyr's damage scales with attack power, thus Crusader theoretically can boost Hidden Satyr's damage as well.
