Automatic vs Manual
Kei minitrucks are mostly fitted with manual transmission which involves more intervention by the driver for its maneuverability. Newer versions have automatic transmission in which there is less intervention by the driver and there is no need to press the clutch for gear change.
People who drive manual transmission trucks will easily drive automatic transmission trucks. But for the people who drive automatic trucks will take some time for them to adopt to manual transmission trucks.
Though most kei class mini trucks are fitted with manual transmissions, newer models are increasingly being equipped with automatic transmissions. Automatic transmissions allow for ease of operation and let the driver focus on the terrain ahead, rather than shifting gears. Though the maintenance cost will be on the higher side, it will by far compensate for ease of driving on congested bylanes or roads.
If you drive inside crowded places like in cities, you can choose the automatic version. It would be easy to operate under heavy traffic. But if you operate in rural or low-traffic areas, it's better to go for a manual transmission as it has better fuel efficiency than the automatic variant and is also easy to maintain.
If you ask me I'd say that it completely depends upon the individual, some may prefer manual because it is more fun and realistic to drive whereas automatic is comparatively easier to drive as it is clutch free.