I'd have never guessed.

Was very good friends with GM of Toyota dealership, always loved Toyotas, and rode in Tundras all the time, but it took me 5 minutes of driving my Dad's ecoboost to be convinced. Go with the F-150. American, always a plus. Gas mileage will be loads better in the Ford, that saves money over time, possibly to cover any repairs. (Haven't had to do any in my father's) Also the performance is just better. The 5.7 Tundra makes 380 hp and 400 ft lb of torque. Pretty stout, but the 3.5 ecoboost makes 365 hp, and 420 ft lb of torque. And those come lower in the RPM curve so that's more usable power. Even the 2.7 ecoboost makes 325 and 380 I believe. Father has the 2.7, it tows my 19 foot tandem axle boat better than my 5.4 triton, and the ride is super nice too. The ecoboost with the twin turbo will always be more fun to drive. They're peppy, you step on it and they respond. Tundras are sweet, but I've been convinced. Ford hands down.

At the end of the day though, it's up to you. Both great trucks, don't think you'll be upset either way. Whatever you like, go get it, and drive the heck out of it.