Hear. Hear. Wade.
I too do both.
I've found that adding juice, rendered from the fruit (or concentrated) really perks up the flavor and aromawhile adding white table sugar adds the sweetness.
If you're not so much interested in adding to your taste or aroma, just add the white table sugar.By the way, I've also discovered that adding natural sugar adds a cane aroma and taste.
While I prefer natural, unbleached sugar in my hotbeverages, I definatly prefer white, bleached sugar in my wines.