Uh, read closely that the test was "Lube oil filtration", not air. I am less inclined to look for a 2 micron air filter, but I definitely would rather have a 2 micron filter for my engine oil (the only problem is that it is impractical).
Also you have to talk an AC fine dust test with a grain of salt - controlled contamination tests tend to cause somewhat unrealistic failure modes. I will support some of the findings that argue small particles cause a great deal of wear. Large debris causes catastrophic failures - small particles cause premature wear. Believe it or not, one of the most abrasive wear items in engine oil is soot.
