Coming from Aion, where servers regularly grind to a halt in large field PvP and PvE, I think the GCD choices are wise. As gear continues to ramp, and skill speed pushes GCD lower and lower, there's plenty of run to manoeuvre with performance still. It also makes the game a lot more deliberate, and makes non-GCD skill weaving all the more effective. I'd rather a slower game with a higher skill ceiling than a mashfest, like so many other MMOs out there.