Leveling spec

This may seem like an obvious choice to some, but considering how long it's been since I've played this xpac, I'd like some input on what the more effective leveling specs will be. Now I don't expect people to post builds, but please be more specific than "blood is good". For instance, if your favor blood you could let me know which talents are irreplaceable in the tree rather than posting a whole spec or merely mentioning the tree.

As it stands I'm toying with unholy for the strong pet but I'm curious of other, more in tune, opinions.

Blood is my fav leveling spec: Allows you to solo 9/10 group quests (Like pretty much ALL the Elite ones you will find in Nagrad and Dragonblight) Only Ring of of Blood and Amphitheater of Anguish + 1 Elite quest in Dragon Blight is all I could NOT solo from 55-80.

Blood also does a "decent" amount of DMG considering it's healing potential - Yet it lacks somewhat in dungeons because of that while leveling. Then again dungeons will take you 10 months longer to reach cap with than quests.

I usually level with Unholy for extreme AoE capabilities, and Death Strike heals still 15%, so it has good survival. Very nice for random PVP encounters too.