i think most "top" surgeons incorporate a number of techniques in building up a treatment plan. i think VSP is more of an aid to compliment an overall analysis. i dont think much info is available as to what degree doctors rely on VSP in performing the actual surgery.
Understooda lot of surgeons here are using the whole CT Scan/cone beam scan + VSP Orthognathic as an unique feature that only a select few (at least over here) have access to. I was flat out told on a local orthognathic forum to avoid at all costs any surgeon that has not studied abroad.