I would still like to see side by side REAL WORLD dynos. I think the Tundra is making more power than advertised personally. I imagine the 6.2 Ford motor is making decent power @3,000 rpms as well.
Towing my 6K lb dry TT (guessing 7K loaded), and a full truck I get mid 10s @ 55, dips to low 9 once I hit 65-68. I run 87 Octane though. What does the 3.5 EB require? I may try running mid grade to see if it helps when the engine is under load (which I have heard it does).
I am running oversized E range tires. They dropped my daily mpg by 1.5 (16.8 vs 15.2) compared to the D rated factory tires. I lose 4 MPG towing where as the EB loses 10 mpg towing. I can't see constant strain on the EB helping its longevity. That's a big drop which tells me that motor is working hard.
I would take the 6.2 F250 over the F150 any day of the week if I was planning to tow and cost was the same