I would say that most paper filters are loaded with OK media. From all the tests I've seen.. the usual air filter issues are with gaskets failing, or things getting unglued. My Dad's truck came over with a "Speedy Lube" air filter of some sort where the gasket failed and it leaked. Ive seen some Fram cone shapes have the end cap come unglued rendering it useless.
Whenever I get a filter, I take it out of the box, and check the gasketing for plausible durability.. If it's got a good edge, no leaks, and it will glued (slight pressure doesn't cause it to pop apart..) I've marked it as satisfactory and used it in my car.
Filters I've seen fail: some model Fram, some generic Speedy Lube filters.
Filters I've not seen fail: Purolator, Hastings (Both made my Hastings/Baldwin) and Motorcraft.
Most of the time I buy Hastings or Federated by Hastings. If I need o keep late hours I'll go to Advance for a Purolator. The Driveworks filter there looked OK, and it was the ONLY one in stock, so it got put in one of our trucks. We'll inspect it at 3500Mi and see if the gasket is cracking at all.
I like taking a filter out at 12K miles and seeing that it's in as good of shape as it was when it was new... just with dirt in it now... That's what the Fed/Hastings filters have given me since I've used them. The "Lunchboxes" in some Ford vehicles (CV, TownCar, 500) can be hard on the rims on the square filters. The lunchboxes with snaps on one side and pegs on the other have "CUT" the rim on a cheapie square filter. Since I'm watching over 5 Fords, and 1 Dodge, along with many other stragglers that show up at my garage door... It's nice to have a filter maker that's shown good consitency and value.