You'll get all kinds of opinions here from "you need a F550 super doody diesel to pull a tent camper" to " I pulled a 34' 5ver with my Ferd Ranger no problem." Haha
If you are a career truck driver you should be able to tell us how much can be towed.
IMO it depends alot on how far, what altitude and how often you tow. I'd throw some airbags or Timbrens and good tires on a Tundra and pull 10k all day long..........in the midwest. Hook up in CO heading West on I70 and I wouldn't put more than 5 or 6k behind the truck. Tow it a couple times a year, not too far, again 10k not a problem. Full timing in it and have to feel that pig of a trailer behind you every other day, back to a lightweight trailer that doesnt fry your nerves or truck.
That's why you get the wide range of reccomendations.