GW2 graphics are definitely better than GW1. I mean you can google the multitude of videos and screenshots, there isn't much else I can add to that story. Actually, the only thing is the style is very colorful, so if you prefer a noir or darkly art style you might not like the graphics of this game.
The looting is instanced. Meaning you get your own drops (generated by server), everybody else gets their own drops. Other people don't even know what drops you got. The resource mining nodes (for crafting) are also instanced, so if you see somebody run up to a tree to chop it down, don't be discouraged, you can still chop that tree yourself.