According to classical optics, the bigger the mirror/lens, the finer the resolution. That CHN space scope mirror is 2 m while Hubble's 2.4 m.(I'm not sure '300x' refers to width or area )

(The Hubble is a Ritchey–Chretien telescope, I once operated a 16"/0.4m Ritchey–Chretien)

I read future quantum optics will b much better.