Thank you so much Mark, Stonewall, and Dema for your responses. My decision, I believe, is really between Dr. Bertognoli and Dr. Bierstedt. I feel that either choice would leave me in excellent hands. Dr. Bertognoli's office has been extremely diligent about providing timely information and answering all my probing questions. I just heard back from Malte Petersen (Dr. Bierstedt's office) today. Financially the cost of treatment is about the same between both; give or take $1000/$2000 - as Dr. Bertognoli's office does not pick up the cost of hotels or transportation, but does provide discounts and assistance. With this aspect out of the picture, it really is a decision of possible devices. Dr. Bertognoli has suggested using the ProDisc Nova which seems to be a simpler predecessor of the M6. I've heard some negativity about the keeled design of the M6 - so being I'm not an engineer, I would be happy to hear any opinions about that.
Dema, I wish you the best. It seems like we are in the same boat. Please keep in touch and I will do the same. This forum has maintained my sanity and anxiety level while trying to make the best informed decision. THANK YOU ALL!!!!!