My husband filed before FRA but older than 62. I think it's optimum for us. He gets 90% of what he would have got at FRA. I will delay mine until I'm either FRA or 70. So between the two of us we will be able to stretch this SS thing.
Another thing that I didn't know and read from the book by Janet Quinn Bryant , How to make your money last, retirement guide. If something happens to my husband and I'm at least 60, I will be able to get 90- 100% of his current SS. Not sure about the exact amount. But close enough. I can live on his SS and delay mine until FRA or 70.