The person I spoke with[2] said that they will remove about 80% of my stomach, and I should experience most of the weight loss in the first 12 - 18 months.
A few years ago I was really good about exercising, eating Paleo-ish, and taking supplemental testosterone. I wound up losing about 30 lbs, and felt great. Over time, though, I have put it back on.
I'd welcome your thoughts on this. Life is short and I'm unwilling to stay at my current weight.
[1] https://en.wikipedia.org/wiki/Sleeve_gastrectomy
[2] http://pugetsoundbariatrics.com/lapsleeve