Do you agree with rabbi kushner or rabbi kirzner?

i just answered a question, which i have now erased, where i gave rabbi kushner as a reference to learning more about judaism only to realize that rabbi kirzner found kushner's theories to be "unjewish." i firmly believe that you need both sides of an argument to wisely choose the correct path. so i ask, who do you agree with rabbi kushner or rabbi kirzner? would you consider kushner's views as unjewish? and what exactly is unjewish?