I would only do voice surgery if I had worked at it seriously for at least a year, had used a professional therapist and still sounded like a guy. I've heard some OK results but have also heard some really bad ones too. The good ones sound no matter than people who just worked at it. It's a high risk procedure and IMHO is rarely needed to sound female. Also even after the surgery you still have to learn how to speak differently, most of it is inflection and how sounds are produced, not the pitch.
