Sharp edges
Losing them was reason that the F2 was picked up before the F; I think that shutter went up to 1/2000th instead of the F's 1/1000th, but I very seldom found myself above 1/250th on either
These usually high speeds popular today seem to be the product of sensors being too damned fast and people exploring wide-open aperture photography, even when there's no logic to it.
Oh well, guess it's a fun thing to do...
:-)
P.S. Let nobody forget: Canon made the first melted Mars Bar bodies.