it even came with the skin and lots of blubber-like fat around the tough chewy skin
That at least sounds authentic.
Any hairs growing out of the skin?
As for Dim Sum, yeah, it's more of a southern Chinese thing. I would imagine it's popular around Hong Kong, as the English name "Dim Sum" appears to be derived from Cantonese, which is spoken in the south. The Mandarin pronounciation for the same characters would be "dian xin" (pronounced something like "dee-ann sin").
JiaoZi, however, are more of a northern thing. You can kind of tell from the ingredients too. The dough used to make JiaoZi is typically wheat based, which forms a much larger portion of the diet in the north. The south typically relies mostly on rice for grains. That's not to say rice isn't also important in the north. It's just not quite so exclusive there. It's probably about half and half in the north, although I suspect there is a slight favouring towards rice even in the north. There isn't nearly so much wheat usage in the south though. From what I understand, JiaoZi would be more of a special occasion food in the south, while in the north it's just... food. You might eat it for any meal of the day, on any given day of the year.
The only problem with JiaoZi, is they can be a bit of work to prepare. I like them, but I'm sort of a lazy eater, so they're usually too much work for me to prepare.
(My idea of food preparation is grab + eat, or at most grab + dump + heat + eat). Hence, my cooking skill is just about zero. I tried cooking JiaoZi once (ok, dumping + heating premade JiaoZi), and let's just say it didn't go so hot. I didn't account for the water absorption + expansion when you boil them. The end result was an overflowing pot, with the lid lifted about an inch in the air. :blush: