If the motor drive on the Elan II sounds a bit different from that
on the Elan and also seems slightly slower, that's because it is.
The Elan II uses a single drive motor to transport the film, move the
mirror and charge the shutter. The older Elan used two motors, one
for the film transport and one to move the mirror and charge the
shutter. Why do this? Economy is the best guess. Presumably Canon
were trying to keep the cost of the camera down. The major downside
is a drop in film transport rate from around 3 fps to around 2.5 fps.
Most of the time this isn't a big deal. If you want high speed, the
A2/E has 5fps, the EOS-1n has 3fps or 6 fps with the booster and the
EOS-1n RS has 10fps (built in booster). The old 10s, RT and 630 also
were rated at 5fps. These drive speeds are for one shot focus. All
drop in continuous servo focus mode.