Very interesting. Editing code at the level of text is too low, ideally it would be raised to the level of thought. We don't think in terms of characters changing, we think in terms of higher level block constructs. It's not about the increased typing speed, it's about reducing cognitive load and making problem solving more enjoyable. Pairing with the Unison-lang style system of direct AST manipulation could be revolutionary, if the difficulty doesn't prove too high.