Pin versus Slider Disc Brakes

I've been told that someone watched the calipers flex and move on a pin-style setup while someone else was pushing the pedal down while the car was on jack stands. Can't confirm it, though, never done a "test" of my own.

I think the sliders have the additional problem of the pads binding in the adapter, while the pin ones don't. This can be fixed by making sure they aren't too wide, so it's more just an issue if you don't check them and run them hard.