Hard to say so far, but based on patients I met who have done 6 or less cm lengthenings here (most Koreans are very conservative in how much they lengthen in comparison to Westerners, very rarely does anyone lengthen over 6.5cm here), they say they've regained all or pretty close to their previous athletic ability, although I have noticed that the femur patients as a whole recovered better than the tibia patients. One patient here who did 6 cm on tibias say his sprint speed for a certain distance I don't remember went from 12.0 seconds to 12.8 after two years post surgery, which I consider a pretty good recovery. Talking to a lot the patients made one trend stick out to me - stick to 6 cm or less if you want to recover very close to your pre-op athletic level. This is the main reason I decided to stick in the 5-6 cm range rather than go for my original target of 7.5 cm.
I believe the two cases of precice malfunctions here were more or less freak isolated incidents. Looking back on it objectively, I would still recommend the precice, the only disadvantage it has is that most doctors do not let you weight bear with it.
Dr. Lee is probably one of the best surgeons in the world for LL. It's something I've heard a lot of surgeons here say, and he is regarded as possibly the top orthopedic surgeon in the whole of South Korea in LL and deformity correction. Dr. Paley himself even said that he could not have done a better job with the surgery than Dr. Lee did when he was observing him.