This is a bit of an apples/oranges thing since they don't play the same position, but I think it is an interesting question. If you could have Starlin Castro or Jason Heyward for the next ten years, who would you pick? Does Heyward's bat outweight Castro's defensive value? And Castro is no slouch with the bat himself.
NOTE: The usage of the Heyward picture is not intended to influence the vote.