"When two men in business always agree, one of them is unnecessary." William Wrigley Jr.<p>I think you need to distinguish between values conflicts, where you should have very high agreement, and disagreements over strategies or tactics to implement or sell your product.<p>If your co-founder can't make suggestions to improve what you are working on at least half the time I don't think you have a lot of synergy.<p>Michael Schrage studied a number of collaborative teams for his books "Shared Minds" and "Serious Play." He concluded that it was a shared focus on a problem that was larger than they could solve individually that encouraged collaboration. That does not mean that team members agree most of the time.