Just a couple of been there done that or doing that comments.
I would never have a widow over the headboard again. You get heat coming in when it is hot and cold coming in when it is cool (think 40°). I have insulated mine with that aluminum bubble stuff.
I had an Arctic Fox 22H. The insulation goes both ways. In the summer the air conditioner ran less often and was not as noisy as the one I have today. Loved that TT. But as I got older having everything inside one box with a motor under it works out better for me.
Take note of water & holding tank capacities.
Make sure the shower is big enough. A buddy did not think about the corner shower till he used it the first time. His wife loves it…..