Which pop-up truck camper could best exploring offroad?

I would go with either Hallmark or Outfitter the two companies have been in the business a long time.
Really depends on your needs posted and agreement with Hallmark/Outfitter to what you want constructed.
I am sure some of the Outfitter and Hallmark people will pop in to give there personal Experiences with their Campers.
Good luck in your search.
Scott