Here is my non biased, currently non-scientific as I couldn’t find my calipers, comparison of the actuators currently available on the market.
My take after using these is that they were designed around completely different uses.
Kowals actuator was made to shorten throw, with shmups being the main use as stated by the maker himself.
Paradises actuators were made to allow the end user to use non stock switches on a jlf and allow for actuation of the switches to occur. Anyone who has tried d2r-vg switches with a stock actuator will understand the need.
Both actuators serve an entirely different purpose and execute each individual purpose as stated.
Top down shot of stock vs Kowal Vs PAS
Kowal vs stock
PAS vs stock
As you can clearly see, the uses are totally different from each other. Kowals actuator adjusts the contact point between the gate and the actuator while the PAS actuators adjust the contact between the switch and actuator.