Quando usare le eccezioni...
Sono senza parole... è una frase geniale! I can't remember where I initially saw it, but the best advice I've seen for when to use exceptions is as follows:
"Don't pee your pants in order to see if your fly is unzipped."
You should always check to see that you are in a valid state before proceeding rather than throwing a likely exception.
Fonte: Exceptional rule of thumb