here the best independent test of air filter designs, done by volunteers like yourselves who pooled their money:

http://duramax-diesel.com/spicer/index.htm

note how the aftermarket gauze or foam filters are 1-3 inches of water less restrictive when brand new, but clogged up much faster than a good paper filter with many pleats and lots of surface area

Paper and cotton gauze are both cellulose.
Do you realize you can clean a conventional paper air filter with the right detergents and procedure?
(but is it worth your time at a reasonable $/hr ?)

here's my personal test of a KN drop in years ago:

>Date: Wed, 21 Jul 1999 15:12:52 -0500
>Subject: KN/Mopar paper/no air filter/ Quarter mile tests
>
>I was curious as to whether the KN air filter element in
the factory Ram
>air filter housing I have been using for 3 years was truly
less
>restrictive than the paper filter elements.

>Back on RTML there was a
>discussion about whether re-useable filters really filtered
the finest
>dust particles as well as paper ones do.
>
>One RTML reader said his construction company tested
re-useable filters
>and did spectrograhic oil analyis to test for dirt passing
through the
>filters. When the silica levels in the oil went up - the
construction
>company went back to paper filters - and the silica levels
in the oil went
>back down. I can't vouch for this alleged test - but the
story worried
>me.
>
>I had the afternoon free and I decided to test the
acceleration question
>myself. I went to the local Dodge dealer (the same one who
sold me a KN drop in element) and bought a $14 Mopar air filter. It is white
paper, has many
>more pleats than the KN, and bears part number 53004383.
Below the part
>number is printed "Made in Canada" and 38682 and then 05/99
is stamped in
>different ink. The rubber gasket on this paper filter seems
to be slightly
>thicker and it takes a little more effort to clamp down the
top cover on it than the KN.
>
>I went to my home-made quarter mile on Highway 64 over the
Jordan Lake causeway. Remember this may be a little more than a true
measured quartermile, is 0.4% grade uphill, and I am timing
with a stopwatch. I do a soft start with my foot off the
pedal. The 235/85R16 tires with 65 psi never broke
loose or smoked in these tests. Gasoline was 87 octane.
>
>Yesterday (a humid 95F day) With KN element, 1/2 tank of
gas I ran:
>18.75
>18.72
>
>This afternoon ( a humid 95F day) with KN, 3/16 tank of gas
I ran:
>18.81
>18.75
>Average= 18.78
>
>Both yesterday & today with the KN there was mild pinging
when rpms went
>+3750, and then a short burst of rapid 'clacks' when the
auto trans made
>its shifts at 4900 rpm. I have found from past driving that
the pinging
>goes away if I use above 90 octane.
>
>Both yesterday and today there was a KN element in the air
filter housing
>that had been cleaned approximately 3000 miles ago. When I
took it out
>today it showed no signs of visible dirt and was dark red
in color. I am
>using the stock factory air filter housing, with the
plastic cold air tube
>going over to the passenger fender wall.
>
>With the 53004383 Mopar paper filter, 3/16 tank of gas I
ran:
>
>18.75
>18.85
>Average= 18.80
>
>I then took the Mopar filter out and re-assembled the air
filter housing
>with no air filter inside. Everything else was the same -
the plastic
>cold air tube was still pulling air from the fender and the
top of the
>housing was clamped on.
>
>With NO FILTER element, 3/16 tank of gas I ran:
>18.72
>18.68
>Average= 18.70
>
>During these two runs without any air filter it seemed to
me that the
>pinging above 3750 rpm was still mild, but a little louder
and more
>frequent. The noise of the engine seemed slightly louder
without an air
>filter.
>
>I put the Mopar paper filter in and drove the truck home.
I could not
>feel any difference versus the KN filter.

{if I were to run this test again I would use two trucks making the runs together but where the filters were switched at each run, and would probably time 40 to 70 mph accelerations in 3rd gear up a 6% grade hill with 1000 lb loads in the beds for better and more 'real world' relevance}