I think this question you should ask yourself. For example myself I have never used shutter speed above 1/1000 for almost 40 years I have used the camera so to me a camera with high shutter speed is no advantage.
There is one thing though and I don't know if it's true. Many of my old 35mm SLR the top shutter speed of 1/1000 are not accurate so if my Nikon F5 with top shutter speed of 1/8000 and that may not be accurate but is the 1/1000 speed is any more accurate???
You would have to check each camera. My new 35mm SLR was made in 1970 or so, and 1/1000 of a second really is 1/1000 of a second, after cleaning and lubricating and adjusting the shutter.