They're all much of a muchness, although personally I prefer the Pipercross dry foam one.
Cotton gauze I don't like because I can see daylight through the weaves, which isn't great for dirt ingress, and oiled foam I don't like because it's too easy for the oil to find it's way onto the MAF. Ditto with the oil used on cotton gauze filters.
Don't expect to feel much of a difference though
The Pipercross is only a fiver or so more than a new OEM paper one, so doesn't hurt to give it a try.
