Grindy brakes

('02 Octy vRS hatch- standard)

Noticed it a couple of times now.

First time was when I had 4 people in the car and braking hard for a roundabout, second time was on sunday braking hard from around 120 off a slip road.

The brakes just make a horrible grindy noise, like metal on metal or something. The pads have plenty of meat, but they might be cheapos (they have Delphi written on them so I assume they are the standard fit pads). Discs also look fine.

Im assuming the pads just arn't up to the job and their properties change when they reach certain temperatures.

What pads does anyone else use? Im looking for performance over long life as I enjoy pushing the car to it's limits (and she loves it!).