I agree with my fellow AWers Just replace the paper ones more often for max benefit.

You say that you've been oiling the stock paper filter for ever? That's a long time!

whatever works

had one our A6 for 4 yrs (25K miles), no problems, no MAF problems, cleaned twice since installed
 

if you oil it properly it will not harm the MAF, follow the instructions.

Hell, I've used a K&N style (initially a K&N filter, now an AFE Filter) on my pickup for 8 yrs. 97K miles without a problem.

I just dumped the K&N filter that I used for a few years. It started kicking out CEL codes - I bought some MAF cleaner and a paper filter and now no problems. I looked at the sensor closely prior to cleaning and it was pretty gummed up. Bye Bye K&N.

I have to agree that more flow has to mean less filtering.

But I have used K&N filters on now four different cars with no ill-effects.

On some cars the gains are more noticeable than others, but I do not doubt that the increased air flow would equate to additional power, however slight on the better designed air intake systems.

I had over 147,000 miles on my last A6, with at least 75k of those using a K&N with no problems.

I also always used Mobil 1 Synthetic, and it kept the engine running strong with virtually no problems for the six years I owned the car. I used varying weights as well, and found the lighter weights (5W-30) to be the best for the Southern California climate and the base 2.8 engine. I also ran the 0W-40 weight for some time too.

Most performance cars should have air intake systems designed to accommodate the airflow needs of that engine. Manufacturer's spend enormous amounts of money and have, at their dispense, a full time dedicated team of engineers to make every calculation, run every test, and do it all again to make sure everything runs properly together.

That being said, most cars will see an increase in performance if the air filter is removed for the same reason a cars performance will be better when the ambient air temperature is lower. More O2 in the engine surely equates to better performance. A reduction in back pressure from using a better flowing filter will also reduce the load on the pistons that are drawing the air from the intake cycle. This percentage may be higher or lower depending on the stock air filter/intake design.

My .02