I'll throw my hot air in the mix, perhaps the reason the bypass filters work better is because the oil flows much slower through them. The heavier stuff could settle to the bottom (as I've seen when changing them). (No scientific facts to back this statement up) It just seems to me that if the oil is flowing slower, then the filter can do it's job better even if the micron rating is larger than other filters. Keep in mind too that as these filters do catch trash, the area for other trash to get through will get smaller.
That's my rant good or bad.
