Great design. Shame they have had problems. No doubt they WILL resolve them.
Everything has pros and cons. The two pros that spring Immediately to mind are that once you've got the trailer set up, say at a camp site or even out on a trail, you can detach the vehicle from it to fetch supplies for example. The other is that you don't have to convert a perfectly good vehicle into a permanent 2 seat overland camper.
As a preference however, having the tent high up on the roof has its advantages, and I'm only assuming here, that it rules out disturbance by most animals during the night. Whether or not this happens is something others will no doubt know better than me.