My two cents:
Apparently when the oil is cold, and because of the flow restrictions of the paper element, will cause the "by-pass" to open allowing unfiltered (not counting the sump screen) oil to run through the motor. Where as the stainless filter will allow even the cold oil to pass.
As far as which filter traps the smallest particles, here is what I think I know about that. The "ABSOLUTE" particle size on the stainless type of filters is 35 microns, which is pretty small. In other words, 34 microns is the largest piece of debris that will flow through that filter. What the paper filter fans will say is that paper filters filter down to 20 or 25 microns. What they don't tell you is that paper filters will allow particles as large as 100 microns to pass. So, in reality, the paper filters "ABSOLUTE" particle size is 100.
I have been using the stainless type filters since 97', and have had no issues with them at all.
To clean, I use CRC Lectra-solve, basically an electronic contact cleaner. You can get it at just about any foo foo parts stores like auto zone, or kragen. I use the little spray straw, put it inside the filter, and as you're spraying go up and down each row. I like the idea of pushing the solvent the opposite direction of the oil flow. I use one big can usually to clean the filter out thoroughly. The use compressed air at 20 psi to blow it out/dry. The lectra solve is about $3.50 a can.
