This is a brutal one. In all honesty, victim statements are so difficult to assess because they come from such a personal location of subjectivity. It is almost near impossible to assess what should be said or whether what is said is appropriate.
I think that much of the answer is dependent on where an individual is in their own psychological state of healing regarding the crime. I think that if they have reached a level where they have made peace with what was done to them, this impacts what type of statement is made to a judge regarding their own personal feelings about what happened. Conversely, if they have not reached a place where some level of peace has been made, then I think that this impacts their message to the judge. Vengeance has little place in the pursuit of justice, but it is important for the victims to be heard. Parents who must make statements to the judge after the slaughter of their children have to be heard. Spouses who have lost significant others or children who have lost parents do have a voice in the statement process. This might even help the process of grieving to advance. I think that lines have to be drawn when this statement moves towards violence, as the entire proceeding up to this point has been its own statement against the nature of violence in our society. While the victims should have their own moment to express their beliefs, I think that it becomes counter productive when this is an expression of violence.
Yet, in the end, I think that much of my statement to any presiding judge is dependent on what it is I feel regarding my own sense of healing and understanding. I would try to convey this to the judge.