Skill animations do not scale with skill speed, which in time and gear choice make certain abilities completely inefficient to the point of not using them for optimal damage.

My best example for this is the signature move for a Dragoon, Jump. The animation of this move is so long that by the time the animation finishes the recast time for all your standard moves have already been ready for a bit. This will only get worse when the recast times go down due to skill speed.