I have to take issue with your use of the term "legitimate" because that implies that the Chinese are not legitimate. On the other hand, I do "get" what you are saying but in the absence of a widely recognized standard that relates to quality, then how is Joe Average supposed to know? As an example, when dealing with motor oil we have the Society of Automotive Engineers that set standards for that product and the oil containers state that the enclosed product meets or exceeds that standard.
If the Chinese have no problem machining bearing races along with the balls to an acceptable tolerance, then what are we talking about here? Is it just metallurgy? And if that's your claim, then how come thousands of items leave China everyday for offshore markets including North America with bearings in motors and in other places but you don't hear about massive failures being posted on the internet? Where is the irrefutable supporting evidence that Chinese made bearings are truly sub-standard?
When individual components are being selected to be part of a larger piece of equipment, then there are many factors that come into play. How much strain is going to be on a certain part? What does it cost to build the finished product if the highest end materials are selected? Is that cost more than what people will pay once it reaches the store shelf or sales floor? Do I want to have a lucrative parts business to go along with the sales of the finished product? What are my competitors using and how successful are they?
In this instance, we have to ask ourselves this simple question. How long should a set of bearings in a mower deck last? If you get 5 years out of the Chinese bearings that cost $2.50 each instead of 6 years out of American-made bearings that cost $12.00 each........ then the math tells you that the Chinese bearings are an excellent buy. On the other hand...... if the Chinese bearings only last 2 years and the American one's last 10 years, then the math is self-evident in that scenario too. Whether my "test" is scientific or not, really does not matter. It is only meant to be an indicator that other owners can hang their hat on because at this point, everyone is pretty much in the dark. All there is to read on this subject is tainted with personal bias, fear, innuendo and mistrust instead of fact and hard evidence. I have a real problem with that.