A friend of mine had it done and it's been fantastic for her. I don't know about the cost or the physical recovery though I think she found the latter quite manageable apart from a couple of episodes where she had to have it adjusted.

I don't know what her weight was prior but I'd say she's gone down from a size 20 to a size 10. More importantly, she's gone from getting very out-of-breath from even just walking to now doing 200km bike rides, being a gym junkie and generally being incredibly active.

She approached it in the right headspace, researched it thoroughly and has followed the doctor's instructions to the letter. She also joined an online support group and says that the people who didn't lose weight (or not as much as they thought) haven't followed the instructions basically.

The hardest thing she found was other people's reactions to her weight loss. She chose not to tell many people she was getting a band and found the constant questions about how she was losing weight quite difficult. She also found that some friends/family were less than supportive of her losing weight, particularly when she was going not just from morbidly obese to obese but from overweight to slim (in BMI terminology) and felt very threatened/miffed that the "fat friend" was now the "hot friend".