I'm thinking for Japanese/Korean cars, there isn't too much of a difference between the aftermarket brands. I installed a Fram in the friend's heapbox(don't ask) and the media felt like the OEM dual-density media with a fleecy bottom layer on the dirty side and a smoother clean side to catch the smaller stuff. The Wix I pulled out with a damaged seal didn't feel as nice as the Chinese-made Fram.
OEM Densos and Roki(Filtech) use thicker and in many but not all cases lightly oiled media. I remember years ago, the Denso air filters for Toyotas had thick, yellow media that was treated and all the Honda OEM filters I've installed were lightly oiled. I'll always use OEM Toyota filters for the parent's van since I feel they seal up a little better and there is a difference between the OEM non-woven(polyspun) filter and the aftermarket plastic frame types on the more recent models. For my car and the friend's Subaru, I'll use a Fram next time.