1974 Duster drilled and slotted rotor question

If you drive like a little old lady you probably will not notice. If you drive harder on the street you will notice a slight improvement. And your brake pads might wear out quicker.

I would say out of probably a hundred drilled rotors I've had on cars over the years, I've only had one crack. It was a new rotor, new pads and I ran it hard on a road course, parked, jumped out and heard a distinct meta "ping" noise. I checked the rotor with a quick visual and didn't see a crack. No more than I drove it again you could feel it. It broke behind the pads. So it's not really common to have them crack.

If you drive like a little old lady, drum brakes will work fine. If you drive like a little old lady and have 6 piston calipers you just want people to look at your car.