To find out or not... The great gender debate

So I know it is totally a preference thing, but I am completely on the fence about finding out the gender.
So I'm proposing a FRIENDLY debate: 
I would really like to know the Pros and Cons of finding out and not finding out. Personal experiences are really appreciated and any opinions as well.
I only ask that everyone be respectful of each other and understand that to each their own- no putting down.