Had time this morning to go test drive a mid height, mid length Transit 250 with the 3.5 Eco-Boost engine.Much better feel then the base 3.7 engine. Had excellent acceleration, excellent freeway power and was actually fun to drive. It had the 3.31 rear axle. Power at 65-70 mph was amazing. The constant downshifting I experienced with the 3.7 was still partly there. You could accelerate pretty much without it needlessly downshifting. But give it just a bit too much throttle and zoom, downshift, turbos start spinning faster and its going 80+ before you know it. After driving both, I'll never buy a Transit for what we're doing with the 3.7 base engine. But the 3.5 Eco-Boost felt powerful enough to handle max weigh against anything you could throw at it. The base 3.7 is a great local city engine. Local contractors with employees driving the trucks will love it. Long haul at high speeds, maxed out for weight capacity, against head winds and up the steep mountain grades, the 3.5 Eco-Boost is by far the better choice, at least for me.
Next stop, go drive a new GM 159" van with the 6.0 and the 3.42 or 3.54 rear axle. Local dealer has a few in stock with the fiberglass cube van bodies installed.