This really is a matter of individual preference, some people feel at home with three wheels and some feel more comfortable with four. They both have their place. There is a common preconception that all three-wheelers are unstable, but to put this into perspective a bicycle is unstable, it falls over if you do not hold it upright or if it is not moving. So knowing bicycles “quirks”, we adapt and happily carry on riding them.
A three-wheeler has its own characteristics. Three-wheelers are more manoeuvrable, have lighter steering, and in the case of the Tramper TWS a better range (because they are lighter and in consequence can carry more batteries). They do require more awareness and care, but in return offer a more spirited and involving, fun drive and they more than equal the four-wheelers capability.
Four-wheelers are not quite as manoeuvrable or responsive, but they do offer a more relaxed drive and will tend to look after themselves, better needing less user input.
So which should you choose? If you can sense and react quickly to the dynamics of driving a three-wheeler, the Tramper TWS three-wheeler may be a good choice. If you use the machine as a tool to get from A to B and do not want to be so involved, or do not enjoy the actual driving so much, then a Tramper four-wheeler may be better for you.