I was doing a search on google for hardy citrus. There is a company selling Shangjuan and of course their advertisement sounded good. So I wanted to check on here and see what people thought about. They list it as cold hardy to 5 or 10 degrees with good juice and fruit that if you add sugar, tastes like a grapefruit. Almost sounds too good to be true, so I just wanted to see if people agree that the tree produces very good, quality fruit.

Normally, when it says "edible" with sugar, they mean lot of sugar. - Millet (1,106-)

Shangjuan = Ichang Lemon (Wikipedia)
It is very aromatic, very soar with a lot of seeds. In my climate it thrived for several years and gave two big harvests. Eventually it is dead after several nights of -12C in the early spring.

I have several young trees, after this week I will know if it can take this cold. there is several trees at ABAC in Tifton Ga. I have tried it but cant remember how it taste. I could get some and taste but I understand it does have commercial values as Dr. Hanna is making it seedless. They are impressive. HARDY CITRUS for the south east says sour grapefruit some off-flavors, fair quality.

I have a tree of about 2 meters high but which has not made fruit yet has this day. It is much more resistant in the cold than the Wilsonii which he in-12°c, has sudden some dégats.
In Europe, 2 products are difficult to find and are sometimes confused.
The shangjuan as all the papeda tends to be sensitive to the hanging dehydration and after a blow of cold
I look forward, the first bloom.