I was cutting at 75 - 100 IPM with a small chinese plasma cutter and at that time the acceleration was 25 in/s/s. When I changed over to a PM65, I increased the cutting speed to 250 IPM (16 GA) but didn't increase the acceleration. The corner cut were terrible. Most were large curves. Most of the advise I got here was to increase the acceleration as high as I could go even if I had to decrease the speed. My machine is maxed out at 225 IPM with 40 - 50 in/s/s (can't really tell the difference between the two). I tried to reach the recommendations in the Hypertherm manual for light gauge but the table wouldn't run that fast.
With that being said, I've designed a new gantry for my machine that will be about 40% of the weight of the current gantry. I am also changing the reduction ratio from 4:1 to 3:1 in order to increase the maximum speed for lighter gauge steel. The high reduction ratio gives much more accuracy than is needed for plasma.
I think each machine is different and has to be dialed in over time to get the best results.