You're not going to believe this, but Engine Masters is testing oil filters in engine power sweeps right now on Motortrend Channel 883 (Comcast Xfinity)
End of Test Update:
K&N Gold Oil Filter wins the shootout test, in terms of highest oil flowrate through the new (clean) filter during engine speed sweep. Advertised filtration efficiency is 10 microns, but they didn't state what % filtered @ that size.
Also, the difference in flow oil flow rate through the clean filter medias was small, ranging from 7.2 gpm only up to 7.7 gpm. That's only a 7% difference in oil flow rates between all the filters tested. All 3 Fram Filters tested were on the low end of oil flow rate (regular, tough guard, extra guard).
Not sure how much contaminant an engine produces over time, but it would have been interesting to see how quickly each filled up.
Edit:
Royal Purple and Amsoil Oil Filters were not tested.