Who knows what US juicers put in their juice? There is no regulation, anywhere, in regards to juice making. While some US juicers do get their juce tested and abide by various self imposed standards, the truth is you really aren't any safer buying US juices, and you don't really know whats in it any better.
I can tell you for a fact that China juices such as Dekang are produced in a highly professsional lab environment, not some dudes garage or kitchen. They are safer and more consistent, and are using base materials sourced from US companies (DOW I beleve, although probably from a Chinese based DOW plant I'd imagine)
Many people don't like PG levels as high as Dekang, or don't like the kind of fake candy-like flavoring they use, some people just don't like buying non-American juice period. But there is nothing wrong with Dekang, it's a quality juice, and I'd debate that with anyone.
That is why I said "from what I have heard" about the China juice. I have always just bought from local vendors, and now mix my own. The taste is the main knock that I have always heard about them, always heard that is a pretty dull taste from all of them. Some have said that a lot of them have a weird after taste. 45mg and a heavy pg....that would be a throat burn to most people. A 50/50 blend at 18mg is the sweet spot for me.