If you pulled the trigger on the EcoBoost, congrats. That will be quite the upgrade from your old tow vehicle.
If you are still in the market, I would look for a used Escalade. More performance from the engine, and a much nicer interior than the Tahoe/Yukon.
We have a crew cab diesel pick up plus a 2500 Suburban. When we are just using the boat, I am almost to the point of preferring the Burb to the truck. If it is just the two big dogs, my wife, and me, the truck is a slam dunk. But when we add another person (or two), and gear, the interior space of the burb is significantly more than a crew cab pick up. I think you will find the same is true on your adventures.