Wait until 70 or collect sooner? What's the worst scenario for each case? If you wait until 70 and you and your spouse both die young, you may not have "maximized" the amount you got from the government, but who cares? You're both dead. If you collect sooner, and one of you lives a very long time, you may not have enough money to live on. That's what scares me.
You've described it perfectly. Each person has to make their own best decision accordingly.