Gear quality
My last thought, doubt all gears are created equal. The quality of steel varies I am sure. Think that the top lines of all makes are quite similar "but" wouldn't bet the farm on the lower cost makes. That said, as was stated earlier, many of them have been installed with little or no problems. The pattern and break in are the issue. All that said, if you are installing to get performance so as to smoke the little "Rice Burners" for the track, or daily driver, probably will never be an issue. The only down side, if your going to be towing for long periods, especially in the hotter climates, would question the cheaper gears. They will never get hot on the strip or street but on the hi way pulling 10k or so and for long periods, 2 to 3 hours, that is where I think you will find the difference. Only "you" know what your use(s) will be. Be cautious