I went to the second speed run, and stood about two-thirds of the way from the starting point. At first I had my continuous frame rate set to 3 frames a second, but then decided I switch to the higher, 5fps rate. In doing so I was able to get a number of Greyhounds with all four feet off the ground, with the dog at full extension (which is a characteristic of their double-suspension stride).
It's such an amazing thing to see:
I used shutter-priority mode for these; the shutter speed was set to 1/2000 second, and the camera set the aperture to f/5.6 at ISO 400. Also, I used one focus area and tried to keep it centered on the dogs' body as much as possible. And I was also zooming out from the dogs got closer to me. I don't have any shots of the Greyhounds as they passed by: using the 70-200mm zoom at the 70mm setting was much too close for me to get the entire dog to fit within the viewfinder.
This is about as close as I'll get to see Greyhounds running full-out, unless I get the chance to go to a dog track, lure course, or NOTRA event.