The real benefit to completing Saga of the Skyserpent is the story you get after turning in the ribbon. Aphmau's connection with the palace is made beginning to be made clear, and Galadar is just nuts.
Led Astray is something you can do when you'd otherwise sit in Whitegate out of boredom. Meat of the quest is just cutscenes in Whitegate, and you can pick up the Imperial silver piece reward whenever you need to pass through Nashmau on your way to do something else.
I'd be more interested in Moment of Truth if the BC turns out to be repeatable. The reward table is based upon the job you are when it comes to reward time:
Strength Potion (WAR)
Strength Potion (MNK)
Mind Potion (WHM)
Intelligence Potion (BLM)
Vile Elixir +1 (RDM)
Hermes Quencher (THF)
Vitality Potion (PLD)
Strength Potion (DRK)
Charisma Potion (BST)
Charisma Potion (BRD)
Agility Potion (RNG)
Icarus Wing (SAM)
Agility Potion (NIN)
Strength Potion (DRG)
Pro-Ether +1 (SMN)
Vile Elixir +1 (BLU)
Agility Potion (COR)
Dexterity Potion (PUP)