I've had my shoulder operated on for a torn Labrum. I guess it depends on what you define 100% as, but my shoulder is stronger and healthier than it has ever been. It has decreased external range of motion but that's because once it go to sufficient ROM for what I needed it to do I stopped doing the long hold passive stretching and just do some shorter duration and dynamic stuff.
I guess the question would be, if I was training and living and eating properly before it happened where would my shoulder have been? The changes I have made as a result of the injury have made it better than ever.
Whenever I ask myself this question I look at some professional athletes who have had a similar surgery as me, such as Dwayne Wade. This is a good indicator of what is possible because he has access to the best docs and care. Do you think his shoulder isn't 100%? He wouldn't be playing basketball at such a high level if it wasn't, his numbers the past 2 years with no help on his team are better than the pre-injury numbers when he had shaq on the team.
I guess all of this though is anecdotal and might be useless info.