Just few statements, unfortunately:

• commercial coffee are everywhere
• robusta added to many blends which make them to heavy and too invigorating for organism
• commercial coffee often comes roasted, while after roasting, it should be consumed within a limited time (e.g. 'Italian coffee')

So the things are better, when:

• coffee roasted in country of consuming
• coffee is ground right before cooking
• pure Arabica

P.S. When you get good coffee, sugar isn't needed, because it have taste instead of just be bitter. Single Origin very good for pour over, chemex or kalita.