The set seems to be particularly sensitive to issues like timing, the order you play cards in, and the little choices you make. The cards don't have obvious drawbacks like Juzam Djinn or Jackal Pups, but they have lots of tradeoffs with the other cards in your deck. Choices like "what do I spend my energy on?" or "how should I fabricate?" or "do I hold on to the Cataclysmic Gearhulk to try and get more card advantage?" So many cards in the set force you to make little choices that add up to quite a bit of mental work.
That said, I'm only playing a sealed league so I know nothing about the state of the game in other formats.