First of all, the fahrrad mit 4 rädern kinder is heavier than the ordinary bike, but it is also longer. Therefore, if the infrastructure is not suitable, it may be more difficult to store them at home or in your city.
Second, pay attention to the battery life and the distance you want to drive every day. If you have a long way to go, you need to be able to ride the battery to and from home. Then charge your fahrrad lasten at night (you won’t find charging stations everywhere). If you accidentally break down, your freight bike will soon become an extra load.