They are gaining popularity, BUT they will flow less and let in slightly more dirt as compared to a Pro Guard 7 AFE filter. Plus there are different ypes of no oil media, AFE's has a higher tolerance in it and it stops more dirt than other brands currently on the market. I was out there a few weeks ago and saw flow testing dtat that had been done on all types/brands of filters and you still have to be cautious as to what type of dry media you get. If you have any questions on the AFE let me know, we should have some here in the near future as we ordered a looong time ago, we know AFE's reputation and knew theirs would be a better designed product than others on the market so we ordered even prior to final design stages.
Mark @ DPPI