Been down that route. Overall, my CEO co-founder was a very honest person; so I've continued our friendship. About 6 months after the business fell apart, he helped me meet my wife and was on the alter when we married.

When we last talked, he indicated that he was going back to what he did before starting companies. I hope it works well for him, because if he can keep within the (not CEO) role that plays to his strengths; I'd happily work with him again.