Air Filter Comparison
Here is a couple of comparison photos of the stock air filter and the NAPA air filter.  The Napa air filter goes for a little over $20, while the Chinese one probably retails around $10.  Photos provided by Glenn.
NAPA with part number on the left, stock on the right. 
Close-up of the NAPA air filter.  The rubber gasket looks like it would provide a better seal than stock.
Close-up of the stock air filter