The Veloped is the only truly off-road capable walker/rollator on the market. In order to be off-road worthy we have designed it as a 3-wheeler, although it has 4 wheels. You can compare it with off-road baby joggers, that are all 3-wheelers. In addition the Veloped has the "Trionic Climbing Wheel" that makes it easy to overcome obstacles like curbs, rocks etc. But in order to offer the required stability, as a 3-wheeler the Veloped is wider and longer than a conventional 4-wheeled rollator.
The Walker is a conventional 4-wheeler like the conventional rollators, but it has bigger wheels (12er/14er), pneumatic tires and the "Syncro Steering" feature that together offer a better outdoor performance and higher comfort level when compared to conventional rollators. But the Walker is not as off-road capable as the Veloped, and it does not have any feature for overcoming obstacles.
A 4-wheeler cannot be properly off-road capable, as sooner or later one wheel will loose its contact with the ground and the Walker comes to an abrubt halt or starts tipping.
It all depends on what you put priority to; if off-road/top performance on uneven ground and kerb-climbing feature = Veloped, but if the width, length and folded dimensions are more important = Walker.
For dirt trails and uneven, bumpy surfaces we strongly recommend the Veloped.