Interestingly enough, some of my coworkers and I were just having a discussion about this recently at the office. One of my co-workers was expressing interest in having this procedure done and the general advice we all gave her was to carefully research what she was considering before going any further with it. The complication and mortality rate for this procedure is far greater than most other surgical procedures currently being performed and the psychological aspects of it are often very difficult for those who undergo it to deal with as well without post-surgical counseling. I believe that for the more reputable bariatric surgery centers, pre and post-surgical counseling is now mandatory.
If it were me, I wouldn't even consider having this procedure done (and I would have qualified for it a few years ago) unless I was faced with the choice of it was either surgery or die in the very near future and nothing else (including following a controlled carb regimen) had helped.
Another interesting point is that many who undergo this procedure wind up following a low carb diet because their stomachs can't tolerate anything else and they need the fat and protein to keep their bodies from going into starvation mode and losing too much muscle mass. Considering that post-surgery, most people can't eat more than an ounce or two of food at one time, they have to eat calorically dense foods to make what they can eat count.