Skill Speed and Warrior

[Alphras]

The WAR rotation does not line up with a 2.5s GCD at all. You need skill speed for a 9 weaponskill Berserk/Inner Release Window without cutting into your GCD (that has been the case since 2.x) and you need even more skill speed if you want to double weave Inner Release and Berserk. The amount depends on your latency.

And seven FCs is a damage loss no matter what.

[Freyyy]

and you need even more skill speed if you want to double weave Inner Release and Berserk

What ? Skill speed doesn't help with double weaving at all. If anything, it's quite the contrary. You can see that on DRK, double weaving is a lot harder and latency-dependant with Blood Weapon on. With too much skill speed on top of it, it's near impossible to not clip your GCD. And you don't need an extra GCD within Inner Release at all since it only affects Beast Gauge costs, so once you're done spending your gauge during your Zerk window, it has no effect anymore. You should be at 0 gauge before your last GCD which is a Heavy Swing, so Inner Release doesn't matter. Having that extra GCD in it is completely meaningless. Only Berserk matters. And you don't need a lot of SkS for the 9 GCDs under Berserk as long as you pop it right before your first GCD inside of it. That's why you double weave in the IR -> Zerk order.

[Lumadurin]

The WAR rotation does not line up with a 2.5s GCD at all.

Excuse me?
Each burst window is approximately 20 seconds.
After finishing, you will have somewhere in the realm of 37 seconds before your next window comes up.
Assuming a 2.5s GCD, each combo is 7.5 seconds.
7.5 x 5 = ~37.
That gives you time for five combos (typically Eye > Block (+ gauge-spender - typically upheaval) > Path > Path > Eye). PLUS a Heavy Swing that you use to lead into your next burst window.
Any SKS is simply breathing room with regards to scheduling.

you need even more skill speed if you want to double weave Inner Release and Berserk.

Since when has SKS ever had anything to do with weaving? If anything it's detrimental because it means it's easier to clip and literally waste your SKS investment.

[Alphras]

If you have enough skill speed you can double weave Inner Release and Berserk and still get 9 GCDs in your Inner Release window. I am talking about using Inner Release and Berserk in the same GCD, sorry if that wasn't clear.

The problem with a 2.5 GCD is that you cannot get 9 GCDs into a 20s window that way, which the WAR "rotation" builds upon. So the most important parts don't line up.

Edit:
Maybe I should clarify this more, since I was assuming this was general knowledge.

The ability of double weaving Inner Release and Berserk enables you to perform the 6 FC + 2 Onslaught + 1 Upheaval window from any point in your rotation after a Storm's Eye (if you are at 100BG). If you need to use these cooldowns separate you either need to start with the GCD after Storm's Eye (very inflexible) or you need to drop an Onslaught, since you'll overcap.

The disadvantage is of course having more Skill Speed.

[Freyyy]

If you have enough skill speed you can double weave Inner Release and Berserk and still get 9 GCDs in your Inner Release window.

Yes, I precisely answered this point in my post. There's no point for the 9th GCD to be inside of Inner Release since it's not a gauge move and you're supposed to be at 0 gauge before this GCD anyway.