Of course. Chang was seriously competitive with the best of his time, reached 3 gs finals and won one, was world # 2. And he played legendary matches, Chang vs. Lendl 1989 is one of those historical events that won't be forgotten. By contrast, I wonder how many people will recall a Ferrer match in 25 years.
Or in short, Chang was an Ozeki (Champion) Ferrer is a Sekiwake. (Junior Champion) ;-)