It's the primary reason I play Ninja, most other classes just incredibly slow to me (I'm used to MMOs with faster GCDs). I believe it was made slow to appeal to FFXI players? Not quite sure, but that game played slowly, and I'd have to assume that played a part in the choice. Regardless, I feel Ninja is perfect. Between GCD, mudras and OGCD abilities, I think the speed at which they execute their abilities is perfect.