What do you mean used after 9-11?
The Black Hawk has been in service since 1979.
The majority of UH-60's are utility, transport, and medivac. They are usually armed with just two window mounted machine guns used for suppression fire. As such they cannot be compared to an AH-64 Apache which is an attack helicopter.
I was a Black Hawk Crew Chief/Door Gunner in the Army. I have over 1600 flight hours in her, including more than 600 combat flight hours.