Robin, with all due respect, I have yet to see any investor read a business plan. They all know that nothing goes according to plan, and in fact, a rule I hear is double the expenses, cut in half the revenue, if you still get a decent multiple probably worth taking a look at. They look at a lot of other documents, talk with others in the industry, drill the founders, etc..plans, not really. This assumes the pitch is tight so as to display knowledge of the business, the industry, the competition, the risks, contingencies, and exit potential, not to mention airtight financials.
Business plans are necessary to get to the financials, and for the founders to think through all the aspects of product, market, operations, strategy, etc. It is not, in my experience, for the benefit of the funding parties.
I would like to hear others' experiences with business plans, i.e., how many funding events are based on reading/passing an early stage/startup business plan?