If you are looking for a substitute for the discontinued Kraft hot drink mix Postum, Pero doesn't taste much like Postum. Postum had a much smoother, slightly sweet taste. Pero has a bitter flavor, which to me tastes like stale coffee. If you are a coffee drinker and want to cut down on caffeine, a good decaf coffee tastes much better than Pero.
By the way, Postum was made from from wheat bran, wheat, molasses, and maltodextrin made from from corn. The ingredients of Pero are malted barley, barley, and chicory; so it is quite different.