Oh, I agree. I'd use results rather than exceptions even if they were slower (and in some implementations they are), because they make the code so much easier to understand and maintain and that's more important the overwhelming majority of the time. But for what it's worth, correctly implemented they can also be faster. And I find that's generally the case: a clear, simple implementation that expresses the essence of the problem will be faster than any number of carefully-tuned edge cases.