My first RTT was just a basic soft cover tent that mounts on top. My newest version of the same tent in hard cover has adjustable LED lighting, more interior storage pockets, an interior zipper that can mount some insulated wall blankets, locking fasteners for the cover, better ladder and mattress, a cover for the ladder so it doesn't chaff when closed. So, there are improvements going on as field testing and feedback comes around. Since they are to do one job in particular there are only so many configurations but there are quite a few.