Very good point on the wrap, I use an amsoil reusable with the wrap... very good, but in the end I find it a pita to clean, dry and oil. I use some foam filter on the off-road bikes and same issues, but the bike filters are smaller so I have one on the bike and one clean one ready to be installed...
As usual, the squeaky voice gets the attention, the unhappy are heard, but the satisfied customers are silent
or go to the test section:
ISO 5011 Test:
The ISO 5011 Standard (formerly SAE J726) defines a precise filter test using precision measurements under controlled conditions. Temperature & humidity of the test dust and air used in the test are strictly monitored and controlled. As Arlen learned in attempting his own tests, there are many variables that can adversely affect filter test results. A small temperature change or a small change in humidity can cause the mass of a paper filter to change by several grams.
To obtain an accurate measure of filter efficiency, it’s critical to know the EXACT amount of test dust being fed into the filter during the test. By following the ISO 5011 standard, a filter tested in Germany can be compared directly compared to another filter tested 5 years later in Rhode Island. The ISO 5011 filter test data for each filter is contained in two test reports; Capacity-Efficiency and Flow Restriction.
and the whole article found on the nissan owner club , nicoclub, mentioning test with filters for diesel duramax
http://nicoclub.com/archives/kn-vs-oem-filter.html