Based on what? Your PhD in Mechanical Engineering? Do you have any published technical papers that you can show us? Vast experience in camera shutter design? You cannot make such sweeping statements without some proven technical reason that you can point to.
Apropos post 36:
Perhaps you didn't mean to come across as churlish as that reads? But, I'm rather surprised to find controversy about this point. The format being discussed is 35mm, yes? Nominally, 36mm x 24mm in size, with cameras using it having a film gate of similar dimensions?
At times shorter than in the X synchronisation speed of a focal plane shutter (let's assume it is synchronised) the effective exposure on the film (setting aside, for now, such variables as the precise distance from the curtains to the film plane, and the focal length of any lens fitted) is going to be the product of: the curtain slit width x the curtain velocity. This is not news? Surely?
Elementary level mathematics should reveal that, for any given curtain velocity, a set of curtains can traverse a 24mm distance in less time than it will take them to traverse 36mm. Surely, this is not controversial, either?
Thus, a few scenarios can play out.
For example: with less distance to run, the vertical curtains running at an identical velocity to those in another, horizontally running shutter, will (if the same slit width is employed in both) yield a shorter exposure time than the horizontal. Remember: slit x velocity. The vertical takes less time!
Alternatively: the vertical could use the same slit as the horizontal type, but run more slowly, and, yet, still produce an exposure equal to the horizontal.
In yet another scenario: assuming again, that both designs use curtains running at a similar speed, a particular time (say, 1/1000) could be attained by the vertical curtains using a wider slit width than the horizontals. The shorter elapsed time (compared to the horizontal) negates any increase in exposure that would otherwise occur due to the wider slit, and the exposure of each can still be the same.
In the real world, various examples of classic vertical and horizontal shutter designs won't necessarily cooperate by halving or doubling so neatly, with such round figures—but there's no reason why (within certain limits) they couldn't.
Slit x velocity. Or velocity x slit, if you prefer.
With a shorter race to run, the vertical shutter has a simple, fundamental, advantage over a horizontal type at exposure settings shorter than 1/1000.
This isn't new. It's not controversial. It's not even technical. It's just grade school maths. But don't take my word for it. Lipinski covered all this, and much, much, more as far back as the mid 1950s, and I seriously doubt his treatise has ever been bettered.
Regards,
Brett