There are guys that will say stay away from the 5.4, however the later 5.4's were actually excellent motors, and produced some decent power numbers, almost 400 ft/lbs. The early ones did have issues with plug blow outs, cams etc. The 09-10's were also pretty fuel efficient overall. These same type of people will also say to stay away from the ecoboost, yet there have been very, very few issues with this motor, 11 and first half of 12 had issues with condensation build up with the turbo causing decreased performance and cut outs. Ford fixed this issue with a plate, cutout, allowing proper draining. If you can stay out of the throttle you will get close to spec mileage, but most guys like having fun with the twin turbos and are always into them. Wind plays a key role for the ecoboosts, if its windy, you aint getting crap for mileage (with ecoboost or about any other pickup), but the mileage decrease in the ecoboost will be more noticeable in heavy winds. For towing, there isn't another motor that really compares in a half ton currently. The 5.0 in the same pickups is a good, plain jane type runner, but a heavy load and its a dog down low.
Gm makes the most comfortable highway ride out there, whether its a 6.2, or a 5.3, they both pull solid mileage, but neither are a crap for towing anything overall heavy. For a boat and smaller trailers they are fine. Get into anything 6-7k+ and its a shit show.
Haven't been around the newer Dodges, but have heard some good things, again, as long as heavy loads aren't pulled.
The new toyotas are bad ass rigs. The ride isn't that great, but they are def. tough machines. Mileage sucks on them, but fun rides and seem durable.
Just made a 1,000 mile round trip to Wyoming in a F250 with a 5.4, pulling 8,000 lbs. 30-35 mph direct headwind on the way home. Pickup has 175,000 miles on it, and a 5 speed manual with 4:10's, she stayed in 4th gear the entire trip home, 70 mph, 3150 rpms, the entire time. Pulled 7.5 mpgs. I was actually happy. If you take care of them, any pickup, any brand, they will last.