Supporting Sponsor, Overland Certified OC0018
Hi Jfet,It's been touched on a few times in this thread. But a good camper is not just the sum of its parts. Furthermore, a great camper is one that has been designed holistically from the ground up. And iterated on after many tests and trials.
Things that are just not inherent in a one off, let alone one that is designed by a layman. These qualities are incredibly cost prohibitive to design in, compared to ATW or Earthcruiser that have amortized these costs over many builds/iterations.
Regarding your comment about few if any production campers having enough headroom for a 6'8" guy......
You may not realise this but the production campers mentioned here have around 7' headroom!! I would think bed length would be a major concern for you though in any production camper. As an example, our mattress is only 6'10" (2050mm) long x 4'10" (1450mm) wide.