If gold rushing if finishing a production with gold then I do it all the time. Later in the game when I have more money, I'm starting wars, and I'm capturing cities it is essential. I hurry the production of my tanks when I need them. I hurry the production of theatres and libraries for my newly captured cities to expand their cultures. I usually have money to spare, or I turn my science rate to 10% for one turn to make some fast cash.