People are downvoting you, but as someone who only worked on a FIX application in a tiny finance shop, microsecond was barely acceptable. The comment rings false with me as well.
What do you mean that 'microsecond as barely acceptable'? That was too long for what?
I'm skeptical that there are really that many players out there who are in a position where a single microsecond would really make a difference. There are definitely companies out there in this situation, but not many.
