Kirin needs much preparation, it's pretty much 1-shot jutsu, supposed to be unavoidable and holds immense striking power.

Throwing rasenshuriken can be used more times, does not require long preparation kirin needs, also has got immense striking power. If used correctly (like Naruto uses it now) it is Rasenshuriken hands down IMO.

Kirin being unavoidable is just autoaim, just another Uchiha haxx :P And Itachi basically proved this assumption not true ( imagine Naruto's kage bunshin being struck down by kirin instead of true Naruto cause sharingan can't see which one is real XD )

edit: changed "shit" to "shot". "1-shit jutsu" sounds amusing, though