filing the edges of the pads didn't help anything, just gave a place (a recess) for debris and stuff to collect and wedge under the pads on the leading edge....
bummer.
any time I "re-surfaced" a pad, I made sure the things were flat, and had crisp sharp edges, which scrape anything off the disc instead of allow it to migrate under the pads.
I know the EBC HH pads are substantially thinner then the OEM's when I measured them.
they don't leave you much to shave off to get a new surface... I think it was like .140" new