I am not talking about a particular power setting varying in its flash duration from one shot to another; I would expect that to be rather consistent.
What I mean is if you are setting up a shot using more then one head, which is usually the case, you need to have the flashes from all heads exactly the same duration to freeze time properly, without ghosting.
Now producing an image with multiple heads, all at the same power, would be rather boring, but if you are using any Profoto gear that is what you would need to do in order to ensure the flashes are the same speed.
With the Scoros however, you can craft a dynamic image with varying ratios of power and then adjust the speed of each flash without altering the power to ensure all flashes are the same speed. If you are using only one pack, there is even an automatic setting that does this for you.
Now color is effected somewhat and you are limited with how much you can adjust the speed as you go higher in power, but canceling out ghosting for a little extra time in post or using a twin head is well worth it.