Ok, so that's not very fast, but when testing something today, I took a club and just tried to really wack the ball.  And I noticed that for the first time that I can remember, the system recorded a shot (barely!) over 100 mph (45 m/s).  Sadly, I can't hit the ball a whole lot faster than that, but it appeared to be recorded correctly.  There was also plenty of additional room on the screen for the strobe pulses to be pushed further apart and further to the right of the screen.  That means that higher speeds should not be a problem.

Unfortunately, I had the "on" strobe set to an unusually long time (>30uS), so that may have contributed to the blurring that is visible in the ball-spin analysis images.  Which in turn resulted in an inaccurate spin measurement as seen in the mis-match between the second ball image and the as-calculated-spin ball (third ball image).  Still, kind of satisfying.