I'll try my best to answer your questions--they're very valid ones.
I first started looking at surgery about 3 years ago before it was approved in the US. I knew I needed help with my weight and I knew that bypass was not for me. The band seemed like a good alternative. At the time, I decided to give dieting another shot. I lost a little and then got pregnant. After trying another weight loss program after giving birth, I decided to look into lap band again.
The deciding factor for me was the final realization that I *could* succeed with the band. I had succeeded in the past with weight loss drugs (and a lot of work on my part). I just needed the tool to help me lose weight.
Once I decided, I did tons of internet research on doctors. I knew about many MX docs from my previous research. I found 3 local doctors and called around to find prices. I found one that was within my means and scheduled a consult. I very much liked him, but discovered that his experience was not even close to that of the MX docs. When that was combined with the cost, chosing a MX doc was a no-brainer.
Based on the recommendations (or more precicely the MX docs not recommended) on other boards, I narrowed my choice to 3 docs. I then cut out one doctor because I did not want to go to Monterrey--I wanted TJ. I then bought Dr. Ortiz's book and decided to go with him. I called and was able to schedule surgery for 1 month later.
As far as the screening process, it is much different in MX than in the US. My local doc wanted a psych eval, physical, nutritionist meeting, a meeting with a physical therapist, and one month of attendance at support group meetings. The MX doctor did blood work, an EKG, and a breathing eval the day before surgery.
My local doctor did say that some people with a sweet tooth (including people who drink lots of high-calorie liquids) might have a problem losing weight. I think the only other contraindication is for people who have had a particular type of GERD surgery. I guess you could be denied for serious heart problems, uncontrolled asthma, uncontrolled diabetes, or some other problem that would prevent you from having *any* surgery.