The best satsumas I ever ate were grown in Bridge City, TX about 25 miles from here in sandy soil called by the tree's owner "little sweetie". The tree was planted in 1989 after the big christmas freeze and is a selection of owari. Don't know the status of the tree after Bridge City was flooded by hurricane Ike a couple years ago. The fruit were incredibly sweet and tasty year after year, like no other satsuma I've tasted. I have budded a tree that is about 3 or 4 years in the ground. I left 2 fruit on it this year to see. Fruit quality is poor now as it has been for every 3 or 4 year old satsuma I've tasted. I wonder if the fruit quality eventually will be as good as the original "little sweetie"? I have my doubts but hope so.

Another friend with 1989 trees has great tasting fruit but not as good as "little sweetie". Oldest tree I have is 9 years and the quality is not as good as the 1989 trees yet!

Nothing to wonder about

Mrtexas,
I do not know about in ground cultur that much, but from discussions I found, that older trees produce more high quality fruit, but the overall yield is low to very low. For a dooryard tree it might be enough, but for commercial reasons this isn't acceptible, so not many trees on commercial orchards thrive that long...
So from my small experience on Clementine and Satsuma it is reported from egypt and Tunesia, as well as from New Zealand and the Kyushu island, that many Satsumas produce a less sweet fruit quality and the first decade of the tree age. so usually fruit is well, but not that sweet.
Climatic influences this, and as later cold appears, as better the sweetnes of the fruit, but since most Owari tend to be an early rippening Satsuma, as more prone the fruit to be picked to late, being somewhat dry and puffy.
So usually fruit is picked if commercial rippening is reached, our dooryard trees can often take a couple of days longer, and may increase a much better taste.
Also it seems that the roostock influences taste, so the fruit wasn't that sweet on tests with Sunki, compared to that on trifoliate stock.
I do not know, how fruit is on other stock, because for Satsuma commonly trifoliate is used, as with many lemon stocks so bud union incompatibilities were found.
From spain many Satsumas reach our markets, usually Owari Selections... but I usually found them much less sweet, compared to the later coming clementines... So the fruit of the spanish Satsuma is often smaller and less rich in flavor, often acid... many people like it...

So I prefer the mediterran mandarine from my own tree around christmas. Rich taste, rich flavor, but fully abandoned from the european market as fresh fruit... But it also took about 5 years, till the flavor was that good, as it is today.

Maybe you find this experiences help full.

BTW: The best Owari I ever tasted was grown in a greenhouse of the tropical Plant Collection of Witzenhausen.
It was green like a fresh picked lime, only a few yellowish specks on the peel, but grown in a nearly Florida like controlled environment of the subtropics - but the taste... sweet, melting and rich... I never tasted any satsuma like that one...

It is clear that climate and age affects the taste of fruit, but how much does the soil affect taste?

Skeeter,
I personaly guess that root development and root activity will influenced by the soil.
So I am sure, a Sweet Orange on Poncirus trifoliata stock in an acid sandy soil won't match in fruit quality the fruit coming from a Sweet Orange on Poncirus trifoliata stock in an acid loamy soil.
Because the later soil is more rich in nutrients and is realy more biologically active, than the more sterile sand... and I am sure, this will even influence the taste....
If I have time, I will see if I can find in any publication from the field trials if this believe is true...
But I am believing it...