well, I don't really want to answer that question as I don't want to potentially upset any men reading this ...
In reply to the previous post, in my experience I've had boyfriends who haven't had any trouble articulating what they don't like about me. It's not just women who are more likely to express dissatisfaction. Maybe it more depends on the type of person rather than the gender. Men can be highly critical too, no doubt fuelled by the constant perfect image of women the media portrays.