BAJASVT
FRF Addict
Are any of these filters that much better than the stock setup with a K&N drop in filter?
What do you mean by "better?" Less filtration is going to be better for performance (more free air flow), but that's not exactly good for your engine. More filtration will be better for the engine, but not as good for power (more restriction).
The main benefit of a K&N drop in is that you can clean and reoil it... essentially forever. Personally, I've never been particularly impressed with the filtration ability of K&N filters. Hold them up to light and you can clearly see lots of "holes" in their filter media and I don't personally like the idea of relying on the oil to fill these holes. I feel they're more of an early 1990's fad (everyone had a K&N filter and Flowmaster muffler).
All the mentioned intake systems are going to outperform a drop in filter. The intake system tube will flow more CFM with less restriction than the stock tube. I feel all the aFe filters are better quality than a K&N and the Powercore is the absolute best of the best... it has the highest filtration capability while still allowing the least restrictive flow.
Take all this with a grain of salt, because it's pretty much been proven that these intakes don't really add much power, especially on their own. I plan on adding an aFe intake with the Donaldson Powercore filter mainly for it's filtering ability, not for more power.