I have KAD 6 pot calipers fitted on my RAV, with Ferodo DS2500 pads. Not long after fitting, I had to get the discs skimmed as pad material was transferring onto the disc causing the brakes to shudder.
I bought a spare set of discs. The discs are 2 part with an alloy bell.

The 2nd set of discs have gone the same way - brakes shuddering and its obvious the same has happened again - pad material stuck on the disc. I've been extra extra careful not to hold the car on the footbrake after heavy braking and I could pass my driving test from the use of the handbrake!!!!!

The 2nd set of discs were only put on less than 2000 miles ago. The car is used for 25% fast road use; 70% town driving/slow driving; and 5% 1/4 mile drag starts when I try to make sure that I allow the brakes to cool down after.

I guess that the Ferodo material is just not compatible with the use I make of the car so anyone got ideas for other pads??

I should say that I swapped onto better calipers as the Toyota single piston caliper was awful.

The new brakes don't appear to be dragging. like the old calipers which kept jamming on.