Like Gina, I want to keep our forced-air furnace but like the idea of having a small catalytic heater for our 5er. If I put one in I'll install it at the back of our trailer under the dinette table. That'll mean we can't use it to heat the trailer when we use the dinette as a bed, but since we tend to sleep in the loft and leave the dinette table up most of the time it would work for us. I guess the other option would be to install it mid-trailer just below the existing furnace, but then we'd loose out on easy access to the cabinet space there.
If you put it back under the dinette table, you probably won't be able to sit there while using it either - it would cook your legs. These are radiant heaters, so they work by heating objects, not the air like with a furnace