I sampled one of my in ground xie shan satsumas the other day when I squeezed one and it was soft and already starting to get sweet.
They are already somewhat orange inside, green on the outside. I think one of the reasons they taste so good in my area is they are
so early. They are earlier than any other satsuma I have eaten. Last year a xie shan on my friend's tree was excellent
November 1 when most other satsumas were not ready. However, if you let brand x satsuma hang on the tree until January first
they are IMHO equal to xie sha at least in my area.