Son had finally worked himself into a weekend starter last season as a Jr, but knew something wasn't right, pretty extreme pain every time that he threw. MRI showed partially torn UCL. He wasn't interested in doing full blown TJ and was prepared to hang it up. Internal brace was presented as an option to be back and play his last year out. Surgery last May was a success, started throwing in the fall and ramped up over Christmas break. He was limited this year, mostly on a one inning schedule, kind of a closer in front of the closer role. He did have a period after the season started that he thought that he re-injured it. MRI showed everything was good, just inflammation at the joint/UCL. They put him out for 2 weeks with heavy dose of steroids, and to be honest he was never completely pain free. But the surgery did allow him to play his Sr year of college out and contribute as he could. Now that his career is over, I expect that he'll be perfectly fine and will be able to throw BP if he decides to coach in the future or throw to his future kids. It was perfect for him and his individual situation.
IMHO, internal brace is a good option if you're just looking to milk a year or two more of a career out. If a kid has years left to play or potentially pro future ahead, TJ may be the better option.