I would not call the F2 OEM filter a POS by any stretch of the imagination; that being said I like the GDP kits, but realize that any of the aftermarket kits with a Fleetguard will have the same 5um rating your current OEM filter does.
The Donaldson P551313 fits where the FF5320 does and is rated 2um, the Glacier kits are easy to install and are top quality for a great price.
best thing is it is not under the hood where the fan is blowing HOT air straight onto the filters! wtf?