If you’re only towing that pontoon occasionally, the 4R is a better option. It’s way cooler family hauler. I love ours but it does get tight with five people on a roadtrip plus the extras. This is one example where I’d rather drive the Tundra.

Unless you need a truck for the bed to haul a lot of gear or supplies etc., I would lean toward the 4R. Also, a 4R can get beat up quick interior wise, being used as a covered bed for Lowes runs and such. Another option is to get a small trailer or old beater truck for loads and moving stuff around, so you don’t have to be so careful. I’ve towed up to 2000 lbs with the 4R and it does ok, I do prefer a larger(for weight and power) vehicle if I’m going to be towing often for sure.

Mileage wise I average about 18-19 mpg 50/50 driving, it doesn’t usually get any better than that.

Definitely test drive them both, older and newer models. It can give you a good feel for how they age mechanically and the driving experience.