I prefer open.
True, they never do look like they did when they were alive, but that just goes to show you that "they" whatever that is, is gone, and only the body remains.
It really helps me with the grieving process to see the person one last time, and then to see the casket being buried at the cemetary.
my family has a tradition where family members who have passed away are brought home after embalming and what not and visitation is held at the house. It sounds creepy, I know, but it has many benefits to the family and mourners. You can hold an all day visitation, and it not at some morbid funeral chapel, people can attend the visitation at your home and not have to be even in the same room as the body if they do not want to. You don't have to worry about the timing and arangments and shitty music at a funeral home. Also if you wish, the body can stay overnight, like the last night that they will ever be there.