Does the death of a young, pious believer in the prime of life carry a special reward, or will his youth be compensated for in Paradise?

There is no special virtue for one who dies young. Rather, virtue belongs to the righteous youth who dies upon uprightness, thereby attaining the virtue of righteous youth, as in the hadith (definition) of the seven whom Allah will shade with His shade, among them: "a youth who grew up in the worship of his Lord." And His (peace be upon him) saying: "Indeed, Allah عز وجل marvels at a youth who has no inclination towards sin." As for compensating his youth in Paradise, there is no need to ask about it, for whoever enters Paradise will attain whatever he wishes and desires.