In my case, the pads, rotors, and sensors are all good to go, no metal to metal. I actually experienced what I thought was metal to metal, only It wasnt making the same feeling when the ABS would apparently switch off. when the abs kicked in from my experience with it today, losing some traction on the front when slowing down and the road had a couple little bumps that cause slip on the car, abs kicked in immediately without any more presure, and I got the same sensation. once past the bumpy part, brakes didn't make the contact with harder presure than when the ABS kicked in.
Have the rotors and or pads checked if you suspect metal to metal. I inspeacted mine and they appeared fine.
'92 300CE - Sold
2004 C240 - C7 Wheels
2015 ML350 - P1, Pano, Ash poplar wood, Sport Dinamica interior, Running Boards Keyless go.