sometimes because the brakes are so touchy. You are just feeling the mechanical advantage or greater assist provided by the hydraulic system or in other words the sizing of the master cylinder to caliper cylinder ratios...so for the same effective pressure you apply with you foot to stop in a Z, the BMW applies more clamping force to the pads, therefore giving the driver the feel that the brakes are very powerful..but then modulating the brake pressure becomes much more delicate and annoying. The brakes are good in a bmw though since the rotors have more thermal mass to handle the heat generated during braking...but you can still easily fade stock bmw brakes due to the properties of the pad if you wanted to...its really not that complicated.