It looks cool, but I'd rather see something like that mounted to the back wall of the cab, inside.
If it's a standard cab, yeah. I actually had more "out of the way" storage room in the cab on my old F150 than I have in my F250. The Fords I'm familiar with don't have behind the seat storage on extended cabs, only on the standard and crew cab models. I have under the seat storage for the back bench, but it's really limited.
I keep stuff like basic tools, emergency supplies, a rucksack with a change of clothes and shoes, etc. in the cab. It takes up the full seating area behind the drivers side so there's basically only room for one passenger in the back seat. Storage built into the bed sidewall, like on this Dodge, looks like it would hold all that stuff with room to spare. But I'm likely not buying a new truck for at least ten years, so c'est la vie. :)