As has been said elsewhere, no doubt, the problem with Chancellor is not its effect but is opportunity cost. If you have space in your deck for a Terminal Silver, then there's probably something better to buy instead. And if you have limited space for terminals in your deck, then you want a Curser or Smithy-variant instead of this.
But if you have space for a Terminal Silver and there's nothing better, then Chancellor seldom hurts. For example, if you're going for a non-terminal power $5 like Governor or Stables or Rebuild or Hunting Party, opening Silver-Chancellor is better than Silver-Silver, because it will get you to your Turn 3/4 (or 5/6) buys faster. And for strategies that prefer Terminal Silver to Treasures (like double Tactician or Minion or with Chapelled decks against a Thief variant), then there's no harm in using Chancellors if they're all the Action-based coin available.
Chancellor does get worse once you start greening, so eventually you'll want to stop playing it, unless its coin is an integral part of your engine.