My biggest pet peeve with all RVs (including truck campers) has always been the vertical 90 degree dinette seating found standard in 99% of everything built since the 1960s. Why the industry hasn't figured this out by now is beyond me. Most of these also have very low back support that offers no upper back support at all. Of the 8 campers that we've owned (4 pull behind, 4 TC) I've found that the best way to get comfortable seating for extended periods of time is simply to build your own. There are many options for tri-fold mattresses that have 3 or 4 inch thick sections and can be folded nicely into a couch. Build a simple base, wider than stock and a reclining backrest and you can have a very comfortable couch. Here are a couple examples that I've built for about $125.
Truck Camper couch with coffee table .....

Truck Camper couch with removable sliding dinette table ....

The above tri-fold mattress has 4 inch thick sections so the seat is 8 inches thick and the backrest is 4 inches thick and extends upward to 24 inches.
This is a couch I built for a small 6x8 foot camp trailer. Three inch thick sections (6 inch seat with 3 inch thick backrest) but also super comfortable ...

