Consumer plasmas can output in 60hz and multiples of 24hz. For a typical upper model Panasonic plasma, it can thus output in 48hz, 72hz, and 96hz with various levels of flickering. However, those multiples of 24hz can only accept 24hz as input. 48hz,72hz, and 96hz can't be accepted natively. That's why judders are still present on those modes.
Now, a professional Panasonic plasma can behave closer to LCDs. It can even accept 120hz natively, something not possible with consumer plasmas without hacking.