Starter Set or Core Rulebook?

[Pyromancer]

When compared to the Core Rulebook, what stuff is missing from the Starter Set?
I'm thinking about getting one of them as pdf, and am unsure which one it should be.

 

[egoaz2ca]

Starter Set is the Core book, split in two minus the 10 pages about Sidal Sector, with Fall of Tinath and a few other bits included.