you know my thoughts
fwiw in DD1 4 yr old kinder class this year (she will be 5 in november) shes one of the youngest !! we've had about 6 or so birthdays and they have allllll turned 5, not 4.
im all for giving them the bonus year at home...whats the rush, check out Kathy Walker, shes a big advocate for going later than earlier, i dont see any bebefit in going to school young

ETA DD also has a boy in his class this year turing 6 in october...they need to emotionally and socially ready for school