– the Rambam cancelled chazaras hashatz because he said people who can daven don’t need it and therefore just chat during chazaras hashatz, the people who can’t daven and do need it see the people who can daven chatting so they also chat. Therefore they only had one amidah and the chazan said it aloud so people who could daven said it to themselves and people who couldn’t daven were yotzei the first time. This minhag persisted in Cairo for about 300 years.
– According to Rb Matisyahu Salomon shlit”a chazaras hashatz is a higher madregah than your own shemoneh esrei because gadol haoneh amen yoser mehamevarech.
– The chazan after Reb Rephoel Shmuelevitz’s shiur for mincha always used to say a hoche kedushah except on Chanukah.