Neville, when a chassidish minyan starts at 9:40 on a shabbos, ask around how many of the congregants actually said krias shema. Tell me what you find. Nefesh Hachayim made this point as well. Rav Shwab famously said about the Satmar Rebbe that he would have accepted him as his rebbe if not for the zman krias shma thing which the Satmar Rebbe ignored.
Pronunciations- litvish said Ay rhymes with pay. In Brisk they still speak of “tayreh”. Anyone who had a litvish rebbe knows it’s Teyreh not Toyrah. But those days are gone.
Chassidim say oy. American yeshivas apparently adopted “klal yiddish” which meant saying oy but pronouncing everything else litvish style. so it’s oyb azoy instead of ayb azay.
As the Yemenites, who have meticulously preserved pronunciation mesorah, say “O” instead of “oy”, or “ay” “O” is clearly the preferred pronunciation. “Oy”, which yeshivish people act as if it’s a chumra over the modern “O”, is actually a kula since “O” is more correct.
But at this point, saying “oy” is a mistake is pointless. That ship has sailed as well.