Freelo? That stun is a ranged skill shot thats harder to hit then you think. It doesn't have a ridiculous travel speed, and its width is surprisingly deceiving. The only time she is practically ever guaranteed a successful charm is when her target is already walking straight towards her. ALSO, it is her only form of CC.
Talon, on the other hand, had an instant, point and click, teleport silence, coupled with a decent slow, AND a short invisibility, all adding up to mind numbing burst damage.
Yes, Ahri is still sort of an assassin, but she has no where near the amount of burst damage a Talon can have. Yes, she is more mobile, but she also takes a hell of alot more skill in order to use her kit effectively. She is also not very lane dominant, with pathetic early game damage, and is easier to shut down then you think.