Both tricks work GREAT and will ALWAYS kill with audiences. I think it really depends what type of information you would like to reveal and how you would like to do it. Dark Arts is great for drawing duplication style effects and has a deep psychological background to it. Also, this effect is gimmicked. Think Pink is more of a utility sleight that can be applied to almost all mentalism in some way. It is impromptu and includes a number of presentational ideas.