a notch above

Noticeably better than someone or something else, though not by a huge margin. The sequel is a notch above its predecessor in terms of its direction and production values, but as far as the plot goes it is just as atrocious. She's definitely a notch above the last presenter they had running the show.

notch above (someone or something)

and a notch better than (someone or something)

Fig. a little higher in quality than someone or something. This latest candidate we interviewed seems a notch above the rest, so let's hire her. That telescope is a notch better than the others in terms of magnification.