Gallen deserves to be more famous than he was, he could play funny guy, good guy, bad guy, he could sing and act. In his Era, few could do both, except Leslie and Andy, both of them were very famous, but Gallen wasn't. Think about it, Jacky could sing but not act, Felix and Michael could act but not sing, Gallen is among the most talented in his Era but he never gained the popularity he deserves.
Gallen's acting skill was top tier in TVB. He can play all kinds of roles convincingly well, whether as good, evil, funny, weird, cunning, or just a plain normal guy. And of course great singing voice and musics.