All my flashlights turn ON and OFF with the same action and I won’t buy any flashlight that doesn’t work like that. It’s a personal preference

But apart from the long click for off, there are more differences between manker and zebralight, such as:
-Build quality, much better in zebralight
-Quality control: manker doesn’t seem to have a good QC
-Efficiency: Zebralight is a step forward here, for example the new U12 looks very inefficient
-Lumens, at least my Manker T01s: claimed 400lm in turbo but barely made 270lm in my integrating sphere, whereas my SC5W II makes 470lm measured