I don't think anyone disputes the torque advantage. I'd argue that these turbo gasoline engines are still a ways off from offering true "diesel-like" performance, but certainly they offer better low-end torque compared to most conventional v6's and v8's. These ecoboosts are somewhere in between naturally aspirated gasoline engines and turbodiesels in terms of torque ouput, but they're also somewhere in between the two in terms of complexity: direct + port injection; injectors, turbo-chargers (and all the associated plumbing); ect. A lot of newer gasoline engines are also starting to integrate EGR, stop-start, cylinder de-activation and rely increasingly on complex timing strategies to achieve the efficient fuel combustion. HCCI and other complicated strategies are on the horizon for gasoline engines too.
I don't think there is such a thing as a "simple" engine in this modern era; rather there are varying degrees of complexity. The ecoboost engines are certainly complex compared to even modern v6's and v8's; the modern diesels probably more so. There have been some diesel breakdown's that have left people stranded on the side of the road; there have also been ecoboost breakdowns as well. Any discussion over which engine type is going to be a safer bet over the long run becomes nitpicking after a certain point....modern engines are more efficient, more clean, and more powerful compared to their predecessors, but there is a price (literal and figurative) to pay for that technology.
My take is that if I'm going to deal with gasoline's mediocre efficiency, I might as well use an engine that has a bit less complexity. An appropriately-geared v8 can still offer very good low-end torque (Tundra)...perhaps not as much low-end as the F-150's 3.5l ecoboost, but still more than sufficient for the purposes of a truck. The Ranger seems to be alone in the low-end torque department within the midsized segment...except for the 2.8l diesel Colorado which still takes the cake both in terms of efficiency and torque delivery.
I just don't see the point in buying a more complicated and more expensive gasoline engine that is trying to be "diesel-like." If you want "diesel-like" performance, just get a truck with a diesel engine; that technology has a proven track record within the truck industry at this point.
21-24 mpg in combined driving. Heck, the 2.8l diesel Colorado can get about the same in combined driving and north of 30 mpg on the highway, despite all of the emissions systems in place. Based on what I've seen so far, I just don't think gasoline engines are anywhere close to rivaling that.
And yes, those diesels, even the overseas ones, do cost more to maintain and operate compared to petrol engines (at least in the short term)...but plenty of consumers flock to dealerships and hand over their hard-earned money for those diesels, especially in the truck/suv segments. Why? Likely for the same reason that so many consumers here in North American opt for the 5.7l iForce v8 over the 4.6l v8 in the Tundra, or the 3.5l ecoboost over the 2.7l in the F-150, or BMW's inline-6 S55 engine over the base N55 engine. People who want more performance are willing to pay more.