Panels are generally better than pods unless you make a cold air feed for the pod. The problem with all e-series cars is that the intake scoop is on top of radiator shroud(this area gets hot) then feeds top to bottom in the air box. Holden use a better idea and take the air from behind the passenger headlight(much cooler) and air feeds from bottom to top. Quick and cheap mod on all holdens VK efi-VS commodores is to hole saw 100mm directly through the bottom of box and then run 100mm flexible piping down under wheel arch.
I am using a K&N Pod at the moment running off a XH snorkel, I find that I get slightly better top end urge using the Pod than the K&N panel which I also own. The difference is negligible though and the Panel looks heaps neater and is good as it is roadworthy!
I run an EF Air box in my car with a RushO2 performance air filter (RRP $100).
I could not notice any difference between this filter and a $7 supercheap auto filter... seriously.
The air box itself has some flow restrictions, so IMO, panel filters are a waste of money unless you sort that out first. On the other hand, its hard to beat a 3" pipe connected to a pod in the wheel arch, thats if you don't mind cutting holes that is.
As for ram air, I think everyone at the last Heathcote meet in melb proved that to be almost useless.
Go the panel filter, unless you have a sure fire better way of making a pod work, the factory panel setup is just fine. But at the end of the day, the filter will make zero difference to how the car performs. Autospeed have proven this. I still run stock intake and stock filter (30,000kms on the filter) and my car is still faster than it should be, the Ford setup is just fine unless you wanna run a turbo/supercharger.
By all means spend the money on a reusable air filter but don't expect to go any faster. Any one telling you it does is probably just experiencing the psychological 'go-faster'. If you swapped their airfilter without telling them I bet they'd never know the difference!