From the K&P website:
High Performance Oil Filters
The medical grade stainless steel cloth that we use is consistent across the entire surface and is rated at 35 microns, meaning nothing larger than 35 microns should pass through the material.
The LARGEST particle that was allowed to pass through (paper filters tested) ranged from 48 for the best filter to over 300 microns for the worst filter.
The stainless should filter out smaller particles than the best paper filter.
I like it because you can see all the particles it picks up, every time you clean it.
This will give clues if something is coming apart, like Mr. Bogus said.
Also most paper filters have an anti drain back valve ( which I have tested and after 48 hours, it does drain back), and these sometimes do not work properly and can cause oil starvation. The stainless filter does not have one of these and doesn't need one for our application.
They are more convenient, and overall better for the environment as you don't have the filter to discard on an oil change.
The Suzuki manual recommends changing the filter every second oil change and with this one I do it every change - more peace of mind for me.
I got my at Shnitz (a sponsor here);
Filter, Oil, Stainless Steel, Micronic - K&P * Schnitz Motorsports Inc