I would bet they're from the same Asian factories.
For the most part they are. Enco and Shop Fox buy the same products as do HF and Grizzly, but have them painted, along with the logo, different. Some stuff is good, and some is not.
I have not seen anyone, but Grizzly, have this little mill, though. The good thing about Grizzly is the warranty they have, and a large parts department.