I use the Amsoil EA Air filter. I haven't opened up the engine so I can't say this filter works better than a paper filter. What I can say is that Amsoil guarantees the filter for 4 years or 100,000 miles. This is realistic compared to the 1 million mile of the K&N filter. Also cleaning is a breeze, you either vacuume the filter or use compressed air, no oil or washing. Good luck on your selection.
I have a foam air filter simaler in design to what amsoil used to sell, but made by a differnt compeny, and have been compleatly happy with it, if they made a micro fiber air filter that fit the VX then I would get it, when I replaced my throttle body I looked in my intake, and with the foam air filter on there for at least 100,000 miles of use befor I bought the car, it was extreamly clean, much cleaner then my motorcycle intake after the K&N that I have replaced with foam.
I'm not sure if there's any solid data out there on paper filters vs. high-flow designs. I run a K&N factory cone replacement, and I'm not sure at all if it helps or hurts. But, it's taken a lot of abuse through the miles of experiments: Hot air intake, damp conditions, etc. I hear that it helps at WOT/high flow operation and not much else.
Honestly, I'm thinking about going back to paper by Fall.
The biggest problem with any oil element filter (K&N included) is that the oil in the filter will get sucked into the intake thus gunking up any airflow sensors you've got in there. I was running a K&N on my truck, started having rough idle and mixture problems, pulled the airflow sensor and found it gunked up with oil residue.
I ran a K&N, saw no difference in power or fuel economy. If it did make a difference in power, the SOTP meter didn't feel it, and they are a pain to clean and reoil properly. And, I've spoken to a lot of people who found dust in their intake path after switching. I went back to paper, it's a lot easier than the mess with oiling the K&N. Total waste of my money too, the filter and the oil and cleaning kits cost the same as paper filters in the same amount of time, especially when you take the dollar cost of your time into account.
For the record, I've driven one vehicle almost 400K miles, and my mom's truck is over 400K miles now. Just about halfway to a million. And the way they are overcomputerizing new cars these days, I imagine my little 87 will see more than a million miles while I own it, barring any accidents.