I've had the Douwe Egberts coffee concentrate thing at three different locations that I've worked for, including my present location. It DOES taste different than brewed coffee. To me, it actually tastes like instant. The nice thing about this kind of coffee, for restaurant service, is that you don't have to wait to brew a pot. You just pull the handle, and dispense a cup, or a pot, at a time. Also, you don't have as much waste, as you don't have to toss the coffee out after an hour, as with regular brewed coffee.
Now, to show my coffee heresy, I actually prefer instant/concentrated over brewed coffee. The brewed stuff is just to harsh for my stomach.
I'm not sure how Douwe Egbert's makes the concentrate, but I wouldn't be surprised if it's a vacuum evaporation process, as "boiling" brewed coffee makes it bitter. This would make it rather hard to duplicate at home.
I've heard that the concentrate idea was to help prevent theft, as you wouldn't have the machine to reconstitute the stuff. But, like all inventive people, all you really need to do is combine a little of the concentrate with hot (not boiling) water, to make it.
I even have a recipe for a coffee-flavored ice cream pie that uses that concentrate. That recipe was developed by one of my old chefs, because we would get one or two packages of the concentrate that were leaking. This way we wouldn't have to throw the thing away.