DBS is serious stuff. It's done frequently ... but is still brain surgery. You are certainly taking the correct approach in soliciting information from those who have had DBS - the stories, rate of success, side effects, etc - are best from those who have had that experience - not necessarily those promoting it. I commend you!
I have not had DBS, so cannot address it personally. I know many who have had DBS. I ask 2 questions: 1) On a scale of 1-10 with 10 best: 1) How would you rate your PD before/after the surgery, and 2) Would you do it again?
I have a friend who has had DBS and belongs to a DBS yahoo group. They might be a resource of folks who have had the surgery or are knowledgeable about it. I think you have to become a member (it tells you the steps).
The yahoo group is: http://health.groups.yahoo.com/group/DBSsurgery/ I'm sure there are other sites.
Best of luck!
Life is a dance. Don't sit it out. ---- Jackson H. Brown