Having just purchased a different trailer, the automatic brake system caught my eye. In other forums, users of the system report no drag and good progressive braking. The actuator applies the braked only when the trailer is going faster than the bike, ie pushing the bike. As soon as the push is relived, so are the brakes.
I wonder if they have brake actuation in the case of trailer separation? An unfortunate accident for camping gear or children turns more serious when a dog is involved.