Storm's Eye Is a Chore

[Shurrikhan]

You still dont want to use onslaught on cd. And still sit on it

Yes. That's the point. That's also why Onslaught is a far superior mobility tool to Intervene, Rough Divide, and almost always Plunge. If Onslaught saves even a fifth of a GCD in melee uptime it will have made up for its cost, but unlike the other gap-closers it isn't used on cooldown and is therefore always available (except for the 10 seconds after obligatory use during Inner Release). Giving it no gauge cost would be a nerf to Warrior mobility.