Goodmorning and Happy New Year. I am not sure whether you are mostly interested in other women's views, but I can give you some information from the medical point of view.
First, let's be sure we are both using the term "Barbie" in the same way. Doctors in this field, when they use this term, mean that the inner lips of the vagina are completely contained and hidden inside the labia majora (outer lips). The outer lips tend to be more or less flat. This is the least common shape of vulva, yet the most "desired" one. As with other kind of esthetic procedures, every person has her own view, regarding what is "best looking" and what makes her feel confident and happy about. This would, in most cases, make them enjoy their sex life more. What I am trying to say, is that for the same kind of procedure, you may hear the full spectrum of answers, from "very happy" to "disappointed".
What I usually advise my patients, before proceeding to something very drastic, is that it may be a good idea to try non-surgical options first, to see whether this is the result they wish to have. Although the result of non - surgical options is not permanent, it is also something that nobody would normally regret having. There are fairly recently introduced "fillers", usually hyaluronic acid, just like the ones used on faces, but specifically designed for the intimate area. Their effect lasts up to two years and are applied under local anesthetic.
Of course, the option choosen, depends on your individual appearance, wish and other factors, such as wish for feature vaginal deliveries, etc.
I hope you found this helpful.
Andreas Bazeos MSc FRCOG