I don't think the two are comparable at all. Invariants are like tests or assertions, debugging deals with issues that are not handled well by either. You debug

I don't think the two are comparable at all. Invariants are like tests or assertions, debugging deals with issues that are not handled well by either. You debug more when you invariant or test less, but one isn't a replacement for the other. You can't step through code or examine arbitrary registers with an invariant.