I was thinking about it this weekend and the discussion around "successful surgery" goes around and round. Would I call my surgery with Dr. UM a success? No, I'm in just as much pain now as I was before the surgery. However, from a pure surgical angle, she did repair two SH's (one on each side), remove mesh from my right side, and work through some tangly neuroma I had on the left side. From her end, and I agree with her, the surgery was successful. So I think success rates and the stats around them are essentially based on one's perspective.
I also think that if you catch a SH in under a year and get it repaired, you have a good chane of healing and returning to your activity of choice. This is likely why so many pro athletes report successful repairs; they almost always get immediate attention at the sign of pain. Anything over a year and you're essentially getting it repaired and going down a pain management road. My .02.