I owned a 2006 Tundra with the 4.7L gas engine. SUPER reliable truck in every way. I sold it because we want to RV more and there was not enough oomph to do the job. I personally do not like the layout and design of the newer Tundra and I wanted to go diesel anyway. I am glad I did, but I get it that diesels are not for everyone.
No way would I ever advise someone to get a new Tundra with the V6. Too big of a truck for that small motor, period. If you do not want a truck for at least medium power, why get a truck???
The first new truck I ever bought was a 1975 Datsun, (pre-Nissan days) and even then the Datsun got better MPG than my friends Toyota trucks, same year. I got 20-21 highway with a 2.0L 4cyl, 4 speed. No OD transmissions for them then. The friends Toyota 4cyl with 5spd and OD got 18. Toyota has always been that way.
My Tundra was rated for 7000 but frankly if you pull 7000 like I was, when you climb a 3 mile climb, at 4-5%grade, nothing huge, and you top out doing 35 mph, foot to the floor, and slowing, I tend to have little faith in their ratings. Through rolling hills it was fine, if you don't mind a lot of shifting.
If it were MY Taco and I was pulling with it, I would not go over 5000, but that's just my experience. The new Tacoma is almost as powerful as the old Tundra was, on paper, but I don't put a lot of faith in their numbers.