Looking at your links there, I see that the Ausom uses a wheel attachment similar to the homemade trailers, where the wheel is supported on either side. Which means the hub can be a regular front bike hub instead of some oddball hub. Seems like that would be sort of advantageous.

I remember seeing a used jogging stroller/ trailer a while back, and noticed the wheels and bearings seemed to be a notch below regular bicycle stuff- more like what you'd find on a stroller, not something expected to last for thousands of miles. It might help if you could look at these in person before buying.