Well said Canocorn; one of the main aspects of collecting that can get lost is the fact that each and every card is individual and unique-- even cards that have been assigned the same technical grade by a grader. In fact, there can be an enormous difference in visual appearance (eye appeal) between two identically graded cards.
Meeting a new card is thus kind of like meeting a new person, I suppose with the important distinction that cards will always be less chafing than most humans, or at least bosses and wives
And I agree with Peter that both 4s are amazing cards.