This isn't orange-related, but
IMHO oranges are one of the hardest fruits to get REALLY ripe like they should be eaten. I know there is about 4 weeks of the year here in Adelaide where I can get A grade oranges from a special organic shop and then the rest of the time I just cant eat them. We also produce more citrus here than anywhere else in the southern hemisphere so its not like we dont grow em lol!
A proper orange is sugar sweet with no tang or acid after taste. You could push your finger into it and it leaves a dent for a few minutes.