> I mean - think about, would you listen to someone who had given 3+ years of blood/sweat to a company and product vs 3 months.

I think both people would be worth listening to. The one who was there for three months would probably have a very different perspective on the corporate culture and management, by virtue of not having worked there long enough for those things to seem normal.

This is the same reason some companies get value from bringing in outside consultants -- their different perspective enables them to recognize aspects of the business that have not occurred to the long-term insiders.