I recently tested some of my cameras on an old rickety tripod to test the shaking that each camera showed. A laser pointer was strapped to each camera. Here are the results I saw, observing the light about 30 feet away, and with each camera on "B.":
Canon F-1 (new): 0 shaking. Very damped mirror/shutter. That's probably why they left out a mirror up feature on this model.
Bronica S2: Even with a huge, noisy mirror, very little vibration.
Leica M2: some side-to-side shaking in certain circumstances. This can be felt even when off the tripod.
Pentax k20d: definite side-to-side movement, in spite of vertically-travelling shutter. Impossible to dampen, even on larger Gitzo CF tripod.