air filters? Options

[TSiwrx]

if anyone has ever seen an oem intake system on a 300zx, they know what i am talking about. right now i have a big box in between my headlights that is sucking air through a small inlet on the bottom of the box. i am sure the two k&n dropins help, but i am also sure the bored throttle bodies could use some more. is there really any hard evidence that one air filter is better than another? im sure there is, but in purchasing an intake for the Z, all the tops name brands and their kits were kinda pricey. i ended up buying a MAS adapter from HKS and am planning on buying my own filter. HKS filters are foam as well as GReddy, k&n filters are that oiled gauze, Blitz filters are sus stainless steel mesh, is there really a difference between all of them? in terms of price, performance, and longevity, what are your opinions? thanks.

[SCCA Stang]

it doesn't matter who makes the piping as long as the inside is smooth (and the less bends the better) also if it is feasable try to grab as much air as possable from the outside of the engine compartment that is where the biggest gain is...
but apex i vs. K&N.... you also want to make sure that you get the filter that also grabs the most dirt (that is the point) if its only a HP or two it may be more benefitial to get the better dirt grabber than the biggest HP gainer in the long run.... you cant win a race you can't finish due to broken parts

my .02