I prefer to live and die on my own sword.
Often times "investors" are not going to have the industry knowledge you do. They see everything black and white by the numbers. When you're self employed, or have "your balls out"... there is an element of calculated risk you need to account for. Often times, this can create tension.
Having an investor is a lot like answering to a boss. If you're going into business with someone, you want to make sure you both have a few bucks to your name, and are on the same page for the business plan. Otherwise, you will have endless grief.
