I have to admit that I am a hard headed SOB,, but when presented with SAE standard test data it amazes me that people still want to make a argument based on "personal opinion". They'll argue all day long about the filter efficiency printed on the box of their Wal-Mart oil filter but when someone goes out of their way to try to offer specific information it suddenly becomes liberal spin meant to sway the masses.
I've rebuilt more than my fair share of engines over the course of my short life and bore concentricity deviation and the ledge left on the upper cylinder bore is all evidence that the dirt particles that pass through the air filter are not simply burned and ejected out of the exhaust. This stuff becomes micro sand paper and when mixed with combustion by-products it does wear away at the cylinder liners over time.
Personally I feel that the air filter is every bit as important, if not more important, than the oil filter in helping a engine last many years.
This being said, I prefer to stick with OEM paper for automotive use. If I had a vehicle that performed its duties in a muddy and wet environment (dirt bike or swamp buggy) I'd likely use a oiled foam.