Are 平常 and 通常 essentially interchangeable?

Question

In a few of my entries on Lang-8.com, several of my Chinese friends have changed 平常 into 通常 and vice versa without providing additional explanation. It it just a matter of personal taste?

Answer 1

平常 and 通常 share similarities, but they are different. Honestly, I prefer using 通常 because when I think of

通 I think of "getting across", "communicating" etc. I think it's more colloquial to hear 平时 in everyday speech.

Answer 2

平常 normal or ordinary. But it could substitute 平时 in some slangs. 

通常 more often than not