Guys, Toyota's offered the Doublecab in 4cyl and V6 since their debut. I sell as many 4cyls as I do V6 models. I think they are both useful for many. The 4cyl buyers tend to be past Camry owners used to the room and space of the Camry but in need of the back bed. And, better fuel economy. The V6 comes with lots of different optional packages that cannot be had in a 4... like the IX package (color match in a few colors), the LL (Limiteds, in certain colors), and an OF package (Offroad package with upgrade shocks, raised white letter tires, and overfenders and alloys, rear diff. lock.
There is an a** for every seat, and there are plenty of 4cyl D-Cab buyers out there. I think many prefer the V6 but it isn't always affordable.
Dianne