We went from a Weekend Warrior toy hauler to an Arctic Fox 811 truck camper and found we wanted more room. Our previous truck did fine with the TH or TC, but we needed to upgrade trucks to go bigger. We decided to go to largest TC rather than largest TH by choosing a Host Mammoth. Before we could carry the Mammoth and still tow our 20' enclosed trailer, we had to upgrade the truck. Going to a Class 5 truck has kept my mods zero on the truck other than outfitting it with a flat bed and receiver.
If you camp in all seasons, sit inside the different units and see if there enough room and comfort for prolonged trips.