I kid you not, the main reason we haven't implemented vault yet, is not because we're worried about security. It's because we're deathly afraid of locking ourselves out by making a mistake, taking the whole system down.
Meaning, this makes Vault more of a "let's really dedicate time to think of every possible scenario" type implementation rather than "let's just keep adding a couple of secrets a week".
What has other people's experiences been?