Well, this thread is getting like the Harbor Freight tool tool debates all over the web. One guy has a HF angle grinder last 20 years when used professionally every day in a bodyshop and another has it burn up cutting thru a third piece of 1" PVC pipe. One guy snaps his $100 Matco breaker bar, runs to HF in pinch, buys one for $10 and it lasts a decade. You get the idea.
The thing that I have trouble believing is the statistical quality control on China parts are consistent from one batch to another. If a company like Moog opened a factory in China, that is one thing. But Dorman or whatever, that is another story.
One batch of joints may last 100K miles, the others will fail in a week. I've seen this thread repeated on many other forums, and there are 20 complaints for ebay vs. one complaint about moog on average. And like others said, feedback means NOTHING, except that the item was shipped out and installed in a timely fashion. I bought some cheap memory on ebay with a lifetime warranty, and 6 months later the seller with 5 figure positive feedbacks just blocks my messages when I want a replacement. Its only $10 memory, but you get the idea. His page looks about as honest and reliable as it gets, talking about quality and lifetime warranties.
China tries to cut corners in every way shape and form possible. As an example, one guy on a MK8 forum has his lower ebay control arm bend after hitting a medium pothole at a moderate speed. You know that is very unlikely on a TRW arm. It is likely the arm wasn't hardened correctly and therefore failed.
If your car was under Ford extended warranty, Ford would only replace it with a Motorcraft or Ford replacement. Believe me, if there was any way Ford and dealers could save money they would, but they also want something with the most potential to last the warranty period, which could be years for an extended warranty. Also, the dealer warrants all repairs for 12mos/12K miles BTW.
Those cheaper parts (OE, Dorman, etc) are designed for places like Midas who give 1-3 month warranties (I was shocked to find this out). The parts are designed for older cars with probably a 1-2 year lifespan, figuring most will be off the road by the time they fail. I was told this by a mechanic.
Then again, considering how money is so hard to come by today I can see the reasoning in buying lower quality parts, every dollar counts. I hate to buy tools in Harbor Freight, but there is no way I could afford Snap on. However, I still think tools are different from a suspension part, I can always stop off at HF after work and exchange a bad tool, but the thought of working on suspension again really makes me think twice.
Ok, off the soapbox for now.