I was a fence-sitter too. Then my husband had the procedure in December 2007 and has already lost 50 pounds!
Now I am having it done next month. I have Blue Cross Clue Shield too (not in MD though).
Here are the steps I suggest to get the lap band:
1. Research online/talk to people to find a competent surgeon near you.
2. Call and make an appointment with surgeon.
3. B/4 surgeon appointment get copies of your medical records for the
last 3-5 years AND a letter from your primary care doctor saying that he thinks the procedure is medically necessary. (b/c BMI is above 40, all of your co-morbidities, etc.)
4. Schedule an appointment with a nutritionist and a psychologist to get the consults done- the surgeon's office may have someone they work with.
5. Have surgeon submit your package to the insurance company- then wait a few days/weeks for insurance to approve.
As of January 1, Blue Cross Blue Shield doesn't require the 6 month diet program before approval. They only require the doctor's letter (showing reasons why it is medically necessary), 3-5 years medical records, psych evaluation and nutritionist consultation.
I started the process March 4 (my birthday) and it has been a crazy 6 weeks of doctor's appointments and hounding my PCP for my records, but I have already been approved.
I hope that helps. Good luck!