My second bimmer, in the early 1980s, was a '69 2500 sedan with auto trans. Several thousand dollars of work had been done to various systems under the PO, but AFAIK was all stock. The booster was the thinner type and I don't know what pads it had, but it stopped wonderfully with light pressure on the pedal, better and more smoothly than the several dozen cars I've had since. Somehow, parts available in the early 1980s could be used to get excellent braking.
Static test the brakes: idling at rest, step on the brake pedal for a minute, the pedal should not, even ever so slowly, sink to the floor. Second: foot on brake pedal, start the car, pedal should sink a bit and brakes should come on fully. Third test: pump the brake rapidly while idling, engine speed should rise. Fourth test: with no one anywhere close behind you, stomp on the brakes, the front two should lock. Fifth test: cruising along at perhaps 35 mph, hands off the steering wheel, get on the brakes firmly and the car should continue to track straight.