what do you think of和what do you think about可以互换吗?

what do you think of和what do you think about可以互换吗?
有人说：think about 一般情况下可以与think of互换,表示“考虑”、
“对……有看法”.如：
What do you think of(about) the film?你认为这部电影怎么样?
又有人说：what do you think of是固定搭配,不能用about
到底是谁对?
大家意见怎么这么不一，有没有比较权威的答案。