NSW vs. Salt Mixes: The Ultimate Debate

[reefer1024]

For many years I have been using Catalina nature sea water (NSW) for all my water changes. I have never had a problem with it.
http://www.catalinawater.com/
Recently some people have suggested to me that this may be risky. The claim is that the NSW may contain all kinds of pollutants and that it is much safer to mix your own saltwater with RO water so that you can control exactly what goes in your tank. This made sense to me, but after doing a little research I found this article.
http://www.advancedaquarist.com/2005/11/aafeature1
As you can see all of the salt mixes tested have concentrations of heavy metals and other elements that are way above those found in NSW. In some cases thousands of times more. I am not sure If these levels are high enough to be a problem, but it does make me wonder.

I would like to know what everyone thinks about this. Do I have to be concerned about pollution in NSW or should I be more concerned about the heavy metals in the salt mixes? Assuming cost and availability were not issues what water or mix would you use?