It's a great surprise when you are told by whoever delivers bubs what the sex is!
You get all gender specific clothes & items as gifts, which is really special!
You don't have to be careful about not slipping out the name for bubs (in case you want that a secret as well)
You can get people to 'bet' on the sex of bubs and them give you their theories why they think it is a boy or girl and see who was right!