Hobao make the hyper 8, OFNA just distribute it in the states. Hong Nor are a completely different manufacturer but are also distributed in the states by OFNA (They make the jammin). Hope that makes sense.
Xray have the best quality, closely foolowed by mugen (but its a more dated design) all the rest are equal in quality IMO. I'm sure someone will debate that but thats about the size of it.
They are all quality though and there isn't THAT much in it.