I have e-track everywhere in my enclosed trailer, but I would be more weary of where I mounted it in a toy hauler due to all of the holding tanks, pipes and wiring on the under side. The e-track does sit up from the floor surface and creates a trip hazard for anyone that does not pick up their feet. If you wanted to recess the track, it is much more work than just mounting it to the surface. I chose e-track because I haul different vehicles in my trailer and fixed mounting locations would have always been a compromise of where I tie down or position. If you know what you are carrying will not change, recessed d-rings are a cleaner design and less work.
Host Mammoth 11.5 on Ram 5500 HD