Originally Posted by
Maveric78f
Harbinger is simply better than Doran, it fetches itself, Doran, mana fixes, and even removal if you are smart enough to play Crib Swap or Nameless Inversion (which is also combo with Doran, as it works as a -3/-3). You also can have a special tech against slivers with Shields of Velis Vel*1 (or mirror entity) in SB (but it's poor I know).
According to me Harbinger is THE reason to play Doran.
Edit : And I forgot, it can just work as a shuffer if you play top (you can choose to search or not, that is to say to shuffle or not). It is also a good blocker of lackey, mishra, isamaru, confidant, meddling mage, ...).