As for the '14 being lighter so the mileage may improve somewhat.....that's kind of silly being the kind of mileage Dodge and Ford are now offering.
For me these "big" mileage improvements are suspect. Don't get me wrong, my 13 combined isn't stellar by any stretch but here is my experience for what it's worth...
I have always got what Toyota puts on their window sticker. Never been shocked in either direction. However, every GM and Chrysler product has trended 5mpg lower than the sticker. Not to say I wouldn't mind 20mpg for reals. I don't buy Ford's Ecoboost claims because everyone I have talked to here in Vegas with one loves it, but the window sticker is a far cry from reality. Of course, they have their mod bugs too, so I usually talk to those with small lifts and bigger tires.
If I was in the market for a truck, I would look at Ford F150 and F250. I really like the F250 series, they always turn my head.
For me, I need the SUV/Truck blend the Crewmax gives. I have an expanding family and I like the comfort. I just got my '12 CM and will drive it for a long time.
I was just talking with wifey last night and said when I drive the Tundra, it's like being on vacation. I love it. It's fun, comforting, and completely enjoyable. Yeah, it's more expensive to drive, but my business pays the gas bill and I don't really drive more than 8K a year.
I am a Toyota fanboy only because of past experience. I've had issues with everything else I have owned with the exception of Mercedes oddly enough (both newer non chrysler). I've owned over 11 Toyotas without hiccup. I'm a fan of turn key and go. I'll pay the man at the pump for that until another brand can sway me into trying again.