I think it is a great shame that boxing fans never saw Tszyu face DLH, Mosley or Mayweather. I'm not even sure we saw the best of him anyway, probably the years 99-02 were his peak as a pro and he did unify the division.
Nearly half of his pro fights were against World Champions so his record speaks for itself IMO. Definitely a top 3 Jr Welter of all time.