Migrate in D8: Great, or Hype?

Everyone is talking about Drupal 8's Migrate functionality, and how great it is. But when you look around, you usually only see examples on writing components of a migration. Never the whole thing. At Drupalcon Barcelona it took me, with help, two days to figure out how to migrate a one node Drupal 6 site to Drupal 8. So we have to ask, is Migrate great, or hype? We'll review the overall Migrate architecture, how to create a custom migration, and propose an high-level architecture for building tools on the Drupal 8 Migrate platform. Come to find out that Migrate is, indeed, GREAT!