Well check it out by all means. That is why I said to test them. You can do a rudimentary test to see if they detect current leakage. I just am not one to put much stock in buying one chinese product over another. I figure they are all the same. I don't buy the Leviton factory and qc stuff.
If I have to buy Chinese stuff, I will not pay for the name of some absentee landlord type company. That is just rewarding them for their decision to outsource. If I saw the prices come down that would be different but at 12 dollars for the leviton GFCI from China I don't see where they lowered their prices for that Chinese cheap labor.
Just for the sake of argument, let's say these devices are built in the same factory as one of the big brand devices.
The big brand companies all have legal representation in the US so, if something happens with their product, they'll be sued and held liable for the damage. Because of this, they use components (plastics, Varistors, Capacitors, relays, etc...) to make the devices that meet some minimal set of guidelines. Set forth by them and/or the safety standard. These components are obviously going to cost more money then a cheaper component that has not been evaluated by a third-party.
The factory building these components, grabs the design and starts building a low-cost copy of it. They use the cheapest plastics, the cheapest electrical components, the cheapest relays and so on. They look the same on the outside. The consumer will never know the difference. The company that is making them, doesn't care because they have no legal representation in this country, they are just keeping their factory lines moving.
This is the same with tools. I briefly worked for a tool supplier, that was getting more involved with importing their own brand of tools. The chinese suppliers gave us the option to have the tool look exactly like a name-brand copy and we could choose from several different levels of "internals", ranging from use it once and throw it in the trash, to an exact copy of the same name-brand.