Go get 'em Judith. I see students everyday who are really not mentally ready to be in the grade they are in. Once they are in school parents, don't want them to repeat a grade, even if they need to academically (they certainly don't want to be told they can't move forward because of their emotional well-being.) Then there's the 10 year olds who are on their way to middle school, without a clue socially or emotionally, who will have to deal with some kids who are already 13 or 14.
In our society people are so ready for kids to grow up so fast---have you been in a clothing store lately?---I cringe when I have to go to the Junior section with my daughter. It is refreshing that you know your son well enough to know when he's ready for school.
By-the-way, the reason we have 10 year olds in Middle School (6th grade) in the state of California is because the law says that the student must be 5 years old ON or BEFORE DECEMBER 2 of the school year in order to start kindergarten.
Who cares what people think? You and hubby have to do what you think is best...