>The camera's release produced a very quiet "click". The MD-2's release
>produced a destinctive "ping", much louder and more "jarring" than the
>camera's built-in release, with more vibration "after the fact".
>The roll of film I shot recently (400 ASA and the 105mm f2.8 Micro-Nikkor)
>was done completely without the motordrive, and I'm wondering whether my
>results were improved due to less vibration from the release mechanism?

The older add-on motors had a solenoid (my headache won't let me spell...;-)
to trip the shutter release on the camera, and these are noisy and add
some shake (the F3/MD-4 seems to have solved this, and the cameras with
built-in motors don't have the problem). For best results, try using the
camera shutter release with the motor on instead of the motor release,
see if that avoids the solenoid "snap" - also, the mass of the motor and the grip help in hand-holding even when the motor is off.