The main benefit of copper free mirrors is the reduced corrosion. As discussed above, this is the rusting that appears beneath the surface of the coating and once this appears there nothing that can be done to get rid of it. Copper free mirrors are 3 times more resistance to corrosion than traditional mirrors. 

Other than the benefits of longer longevity of the mirror, copper free mirrors are also better for the environment. Without the harmful chemicals such as copper sulfate and lead in the manufacturing process, the production of these mirrors are significantly less harmful to the environment.

If we have to compare mirrors then, Copper-free mirrors are the absolute winners in every aspect, they are more resistant to environmental factors. Highly reflective as a silver mirror and also environmentally friendly with lead content of <1 ppm. Their manufacturing process is much advanced which also makes it a higher quality product.