Since I don't have the patience to reconstruct the elegant arguments of my lost post (including the careful and humorous references to Genghis Khan, The Princess Bride, football referees, and Dungeons and Dragons), I'm going to give it to you straight and raw.
Rules are dangerous because outside of natural laws of physics and chemistry, rules are rarely universal and consistent. You don't get the chance to attempt a saving throw to save your business from going under.
Whether or not "Get Big Fast" works as a rule for startups depends a lot on the external environment. Sometimes it is a good idea to get involved in a land war in Asia.
The best rule is consider the situation carefully and systematically, use heuristics when possible to save time and energy, but ultimately to trust your own judgment.
Your VCs care more about whether you build a successful business than whether you follow their suggestions. Google offered $30 million for Friendster, and Yahoo! offered $1 billion for Facebook. Yet Jonathan was wrong to turn down $30 million and Zuck was right to turn down $1 billion.