Has anyone used, or using the Epi-No?

It is an instrument designed to help you stretch the perineum before giving birth to hopefully avoid tearing? My Ob has recommended it after seeing it used by some patients and not by others to great affect. I had kind of dismissed it and told him so, and he said the decision is mine but he doesn't want me to dismiss it just yet. He is the kind of obstetrician that really wants his patients to have a no or low intervention birth so I don't believe he is pushing the idea as something for no reason, because tearing is pretty much an accepted part of birth. As I really haven't done a whole lot of research on it I just thought I would ask here if anyone has used or is using it and what they think?