I'd say I was much less productive. Usually when we were pushing 80 hours weeks, we were getting ready for a big conference that our bank put on - and cranking out loads of monotonous pitch books that didn't require too much mental energy. At least, not too much if you'd done similar ones 100 times before!

If I had had to create a financial model from scratch - or put together something really complex at hour 80 - that would have been a MUCH harder task.