I orignally dislocated my shoulder while kayaking, and after that i popped it out 4 times while skiing, playing basketball, and surfing. So my shoulder has popped out 5 times now. And it sucked.
I went to the orthopod, and he said that i was an excellent canidate for surgery, and physio would just save me in basic situations, but that the muscles couldn't react fast enough to save me if it was really going to pop out. Therefore he reccomended surgery. I finally decided that getting surgery was the way to go. I chose the non-orthoscopic method because it had a lower rate of relapses. It was the best decision of my life.
Since then my shoulder has not popped out once. This is while kayaking the Grand Canyon, surfing, and tomohawk in powder. There were moments where I could feel it starting to go, and then it just stopped and held strong. Best Feeling Ever.
However, the surgery alone was not enough. Due to the shoulder joint being moved around so much, and being surgically altered, it would move around in strange ways when I slept on it. This was something I thought I was going to have to live with for the rest of my life. Then 3 years later, I got a personal trainer who really new his stuff. At that point, he put me on a program that included a lot of shoulder strenghening exercieses. Now I can happily say that I can sleep on my left side as long as I keep a regular gym schedule, which is nothing short of amazing.
So get surgery, work super hard on physical thearapy, and work out with a good physical trainer and you should do just fine.