How the DBS operation is carried out seems to depend on the hospital where the procedure is performed. My surgery was carried out at the National Hospital for Neurology and Neurosurgery, Queen Square, London in 2011 under general anaesthetic throughout, so obviously I didn't feel a thing.!
My personal experience of DBS since then has been overwhelmingly positive.
If you'd like to speak to someone who has been through DBS , may I suggest that you get in touch with the Peer Support Service via the Parkinson's UK helpline. Several of the volunteers, including myself, have had DBS and will be happy to share their personal experiences.
All the best!